55.2-59 Wheelbase - The 1947 - Present Chevrolet & GMC Truck Message Board Network

hotrod1 · 07-06-2021, 01:06 AM

Have a 56 that I am trying to get a good wheelbase dimension (building a chassis).

What wheelbase have you used that looks good in a 55 (2nd gen) to 59?

**mr48chev** · 07-06-2021, 01:28 AM

Scroll and ye shall find. https://www.gmheritagecenter.com/doc...olet-Truck.pdf

When my buddy was subframing a lot of TF trucks he moved the front wheels about an inch forward of where they were with the I beam. His thoughts were that it centered the wheel in the wheelwell better. Your personal taste comes into play there.

my56chevytruck · 07-07-2021, 08:29 AM

Quote:

Originally Posted by hotrod1

Have a 56 that I am trying to get a good wheelbase dimension (building a chassis).

What wheelbase have you used that looks good in a 55 (2nd gen) to 59?

I believe 114" is stock.

**mr48chev** · 07-07-2021, 02:08 PM

114 is indeed stock but a lot of guys installing subframes or independent crossmembers like to push the front wheels forward an inch or so to center the wheel better in the wheel well visually. Purely personal choice but my buddy who was doing that did probably 25 subframe jobs on 55/57 Chevy trucks.

**Hcb3200** · 07-08-2021, 01:17 PM

114 if its the short bed. Just confirming.

BAM55 · 07-08-2021, 01:55 PM

While its true that the wheelbase is 114. On a lowered truck it makes the wheel center line look off (too far back). I always end up moving it forward. You only notice it on lowered trucks and since most trucks with IFS are lowered you will notice it.

hotrod1 · 07-11-2021, 01:52 PM

Thank you, everyone, for your replies. I appreciate it!

dsraven · 07-14-2021, 10:43 AM

if you haven't got one, here is a link to the factory assembly manual. you may want to download this for future reference in case the page gets deleted at some point. this will have frame drawings with dimensions for the stock trucks. note that the 58 and 59 have a longer frame out ahead of the front axle because the sheet metal is longer so the rad support mounts are not in the same place as the 55-57 trucks.

https://www.trifive.com/d1/55-59Assy.pdf

like noted previously by others, if you plan on running a stock ride height then the stock axle locations will work. if you plan to run a lower than stock ride height then the front axle usually gets moved ahead an inch or inch and half. this can vary depending on the tire diameter chosen as well as the ride height chosen. really, it is best for you to have a tire of the size you will install when done, even if it is a baldie, so you can mock it up in the wheel opening with the truck sitting at the ride height you want when done. because the front wheel opening is rounded in the front side and tapered on the rear side the tire looks like it is being stuffed into the rear of the wheel opening as the truck is lowered. the same goes for the space ahead of the wheel if the axle is moved too far forward.
I like your plan to build a new frame. I have seen a lot of trucks with the front of the frame cut off and a subframe welded on, then the rear of the frame cut off and a C notch welded in. I think, really, the only part of the frame that is original is the section under the cab. why not just start from scratch then and have a nice long section of rectangular box steel running fore to aft until it is required to be cut and reshaped for suspension? the frames are pretty straight between the front suspension and the rear C notch. build a frame table from scrap steel you can pick up cheap, level it all out and start building your new frame on top, it doesn't even need to be the same width as the stock frame as long as you keep the body mounts where they need to be. I really suggest you do some paperwork planning and drawing if you haven't already. I am sure if you are up for building a frame from scratch then you probably have the plan figured out.
post pics as you go please, it keeps us interested and motivated to work on our projects.
what do you plan to run for suspension?
here is a couple of pics of one I did a few years back. TCI MII front end with 2" drop spindles. the string is located 1" ahead of the stock axle center line. this will give you about 6-7" of clearance at the rocker panel front edge with the lower control arms sitting level with the ground. tire is a 215/75r15 I believe.

hotrod1 · 07-14-2021, 11:44 AM

Great info - thanks!

You are right - why not do the whole thing and run new rectangular tubing which is what I have done. 65-year-old steel is not the same - twisted and soaked with oil. No Limit front and rear suspension and custom rear notch.

dsraven · 07-14-2021, 11:46 AM

Great. You can dig through the factory drawings till you find the model with the info you need for your new frame.
Post up some pics if you can.

**mr48chev** · 07-14-2021, 02:22 PM

Dsraven's two photos above are a great example of the it's what your eye sees as just right that actually counts.

The little difference between "that's good" and That's perfect" for some.

dsraven · 07-14-2021, 08:52 PM

on my current build I plan to run 235/60r17 tires. (its a frame swap) so the rpm will be ok at highway speeds. that's a 28" tall tire.

dsraven · 07-14-2021, 09:03 PM

maybe helpful links. good to know stuff if doing a new suspension. like before you start the install of the new stuff.

https://www.wheel-size.com/calc/?whe...cl=50mm&sr=0mm

http://www.csgnetwork.com/multirpmcalc.html

https://tiresize.com/comparison/

https://www.suspensiondesigner.com/k...centre-offset/

https://www.motortrend.com/how-to/in...nt-suspension/

https://www.streetmusclemag.com/feat...neering-speed/

hotrod1 · 03-28-2022, 12:10 AM

Hey Everyone

So it has been a while but got back to it.

New chassis (custom) - increased the wheelbase to 114.75". The rear looks about right. The front-wheel looks a bit too far forward. There are no cab mounts on the chassis yet so it can go anywhere. Here is the bed gap spacing from the top and then from the side - which I am not sure what it should be. Thoughts?

dsraven · 03-28-2022, 12:25 AM

personally I would move the front wheel back a bit. is that the size of tire you plan to run and the ride height of the tire in the fender is correct? just asking because the TF trucks have that angled rear front section of the fender opening so if the truck is lowered down more the tire looks like it is getting closer to the rear of the opening, and vice versa.
if you want to see what the factory bed to cab spacing is google 55-59 cherolet truck factory assembly manual and pick the tri5 site. its a free download and has the drawings in there

hotrod1 · 03-28-2022, 12:33 AM

Quote:

Originally Posted by dsraven

personally I would move the front wheel back a bit. is that the size of tire you plan to run and the ride height of the tire in the fender is correct? just asking because the TF trucks have that angled rear front section of the fender opening so if the truck is lowered down more the tire looks like it is getting closer to the rear of the opening, and vice versa.
if you want to see what the factory bed to cab spacing is google 55-59 cherolet truck factory assembly manual and pick the tri5 site. its a free download and has the drawings in there

I would agree on moving the wheel back. I just dont know where to get the space from - the wheelbase is set at 114.75" and the rear wheel looks good. The only thing I can figure is to open up the bed gap more but not sure I like that option.

dsraven · 03-28-2022, 10:49 AM

ok, gonna assume your chassis is done and the wheelbase is therefore roughly set with the exception of the rear axle because you have a 4 link rear suspension which can be adjusted slightly. do you have some pics of the frame without the body on top so we can see what you have to work with?
if the front end is already welded in then that is not moveable but if the rear is a 4 link then that is where you will need to get your wheelbase modification from. if you have made the frame to be 114" and now you are not too sure if that was the best for the "wheel in fender look" then changing the wheelbase would be best done at the rear.
I would say to install tires of the diameter you will end up with when done because the tire size makes a difference on how things looks in the wheel openings.
set the suspension up at the ride height you have dialed the geometry in for during your build and pin it there with some sort of link where the shocks will mount up so it stays at that height. usually the lower control arms are level when you look at them from the front and/or the side
set the frame up at the rake angle you want or you have built into the new frame when you set up the front end and welded it in
set the cab and front sheet metal on and adjust them fore to aft until you get the look you want in the tire to front fender. you may need to fab up some wooden blocks the right thickness so your cab will sit the correct height off the frame since your cab mounts are not part of the picture yet
set the box on at the correct dimension between the cab and nstall the rear fenders. stand back and see how you like the look of the rear wheels in the fender openings. if it isn't how you like it take a dimension on how much things will need to move to make it how you want it. the other thing you could do here, to make things the correct spacing like it would be stock, is get the original stock frame drawing out and get the dimension from the front cam mount to the box mounts and set the box at those dimensions, then do the same for the rear axle centerline. adjust the rear section of the frame accordingly or set up the 4 link bars to get that dimension as long as the C notch will allow that movement without the axle hitting the frame on a full suspension travel. it will be easier to adjust the rear frame section than it will be anything else unless you are OK with having larger gaps in the box to cab area
just my thoughts, it is your truck and your plan so you gotta do what you like
post up some pics of the bare frame if you can, as well as the full side of the truck if thats possible. maybe we can come up with some better ideas.

_Ogre · 03-28-2022, 05:05 PM

did you make the frame or buy one?
i have the same, 114.75" wheelbase on 58 truk
do you have all the rubber mounts under the cab, i suspect your cab is tilted forward?
post up a pic of the bare frame, something is not right
i didn't find a good pic, but my cab/bed is closer than yours too

hotrod1 · 03-28-2022, 09:12 PM

Custom chassis and the cab is just resting on it - the chassis does not have any cab mounts on it yet. Is there a wheelbase difference between a 56 and 58?

hotrod1 · 03-28-2022, 09:58 PM

Moved the cab closer to the bed (3/4" at the top) and then place the wheel where it looks closer to what it should be - 113.5". Your thoughts? Looks like the front cross member will have to be cut out and redone - not going to be fun. I don't have any other ideas.

Here are pics of the chassis.

_Ogre · 03-29-2022, 12:40 PM

Quote:

Originally Posted by hotrod1

Moved the cab closer to the bed (3/4" at the top) and then place the wheel where it looks closer to what it should be - 113.5". Your thoughts? Looks like the front cross member will have to be cut out and redone - not going to be fun. I don't have any other ideas.

most of us have the extended 114.75" or 115" wheelbase and it works great. be very careful modifying your frame shorter. i think you should tack in the core support and mount up the front sheetmetal. then do the same with the bed rails and mount the bed. something is not right, but i wouldn't start cutting your frame just yet.

55-59 has the same wheelbase and uses the same bed and cab. the only difference is the front frame horns are 1.5" longer to allow for a different core support and front bumper mount, made necessary by those sexy 4 headlights

nice frame btw

**Rickysnickers** · 03-29-2022, 10:13 AM

That front wheel placement looks much better. I'm sure it will be a lot of work to move it.

dsraven · 03-29-2022, 10:47 AM

I was going to say it would be easier to move the C notch ahead than to move the front cross member back, but, looking at tghe frame and all that steel in the rear, maybe not.
have you mocked up/assembled the front suspension parts and placed a wheel on a hub there to see how it looks or just going by a plumb bob and tape measure?
that is a heavy duty frame. what is the plan for the truck, are you putting in big power, racing?

dsraven · 03-29-2022, 10:56 AM

gotta agree the wheel placement looks better in the last pic where it is back just that little bit.
did you build the frame yourself? nice skills!

dsraven · 03-29-2022, 01:34 PM

I second ogre's post about assembling the front end sheet metal and advise to assemble the suspension up front and mount a wheel/tire so you know what you have. Set the cab up on blocks of some kind to simulate the mounts and ensure everything is level with each other. Better to start at the front and work back I think, just my opinion. If you have 114" wheelbase then theoretically it should work. Like ogre says, that's what a lot of thesetrucks are running.

07-06-2021, 01:06 AM	#1
hotrod1 56 - autocross Join Date: Apr 2010 Location: Camarillo, Ca Posts: 1,121	Wheelbase Have a 56 that I am trying to get a good wheelbase dimension (building a chassis). What wheelbase have you used that looks good in a 55 (2nd gen) to 59?

07-06-2021, 01:28 AM	#2
mr48chev Registered User Join Date: Jul 2007 Location: Toppenish, WA Posts: 15,731	Re: Wheelbase Scroll and ye shall find. https://www.gmheritagecenter.com/doc...olet-Truck.pdf When my buddy was subframing a lot of TF trucks he moved the front wheels about an inch forward of where they were with the I beam. His thoughts were that it centered the wheel in the wheelwell better. Your personal taste comes into play there. __________________ Founding member of the too many projects, too little time and money club. My ongoing truck projects: 48 Chev 3100 that will run a 292 Six. 71 GMC 2500 that is getting a Cad 500 transplant. 77 C 30 dualie, 454, 4 speed with a 10 foot flatbed and hoist. It does the heavy work and hauls the projects around.

07-07-2021, 02:08 PM	#4
mr48chev Registered User Join Date: Jul 2007 Location: Toppenish, WA Posts: 15,731	Re: Wheelbase 114 is indeed stock but a lot of guys installing subframes or independent crossmembers like to push the front wheels forward an inch or so to center the wheel better in the wheel well visually. Purely personal choice but my buddy who was doing that did probably 25 subframe jobs on 55/57 Chevy trucks. Attached Images __________________ Founding member of the too many projects, too little time and money club. My ongoing truck projects: 48 Chev 3100 that will run a 292 Six. 71 GMC 2500 that is getting a Cad 500 transplant. 77 C 30 dualie, 454, 4 speed with a 10 foot flatbed and hoist. It does the heavy work and hauls the projects around.

07-08-2021, 01:17 PM	#5
Hcb3200 Senior Member Join Date: Apr 2017 Location: Suwanee GA Posts: 274	Re: Wheelbase 114 if its the short bed. Just confirming.

07-08-2021, 01:55 PM	#6
BAM55 Registered User Join Date: Jan 2016 Location: Inglewood, CA Posts: 324	Re: Wheelbase While its true that the wheelbase is 114. On a lowered truck it makes the wheel center line look off (too far back). I always end up moving it forward. You only notice it on lowered trucks and since most trucks with IFS are lowered you will notice it. __________________ BAM 55/58 Chevy Truck Project Fixing a mess of a clip installation

07-11-2021, 01:52 PM	#7
hotrod1 56 - autocross Join Date: Apr 2010 Location: Camarillo, Ca Posts: 1,121	Re: Wheelbase Thank you, everyone, for your replies. I appreciate it!

07-14-2021, 10:43 AM	#8
dsraven Registered User Join Date: Nov 2010 Location: calgary alberta Posts: 8,372	Re: Wheelbase if you haven't got one, here is a link to the factory assembly manual. you may want to download this for future reference in case the page gets deleted at some point. this will have frame drawings with dimensions for the stock trucks. note that the 58 and 59 have a longer frame out ahead of the front axle because the sheet metal is longer so the rad support mounts are not in the same place as the 55-57 trucks. https://www.trifive.com/d1/55-59Assy.pdf like noted previously by others, if you plan on running a stock ride height then the stock axle locations will work. if you plan to run a lower than stock ride height then the front axle usually gets moved ahead an inch or inch and half. this can vary depending on the tire diameter chosen as well as the ride height chosen. really, it is best for you to have a tire of the size you will install when done, even if it is a baldie, so you can mock it up in the wheel opening with the truck sitting at the ride height you want when done. because the front wheel opening is rounded in the front side and tapered on the rear side the tire looks like it is being stuffed into the rear of the wheel opening as the truck is lowered. the same goes for the space ahead of the wheel if the axle is moved too far forward. I like your plan to build a new frame. I have seen a lot of trucks with the front of the frame cut off and a subframe welded on, then the rear of the frame cut off and a C notch welded in. I think, really, the only part of the frame that is original is the section under the cab. why not just start from scratch then and have a nice long section of rectangular box steel running fore to aft until it is required to be cut and reshaped for suspension? the frames are pretty straight between the front suspension and the rear C notch. build a frame table from scrap steel you can pick up cheap, level it all out and start building your new frame on top, it doesn't even need to be the same width as the stock frame as long as you keep the body mounts where they need to be. I really suggest you do some paperwork planning and drawing if you haven't already. I am sure if you are up for building a frame from scratch then you probably have the plan figured out. post pics as you go please, it keeps us interested and motivated to work on our projects. what do you plan to run for suspension? here is a couple of pics of one I did a few years back. TCI MII front end with 2" drop spindles. the string is located 1" ahead of the stock axle center line. this will give you about 6-7" of clearance at the rocker panel front edge with the lower control arms sitting level with the ground. tire is a 215/75r15 I believe. Attached Images

07-14-2021, 11:44 AM	#9
hotrod1 56 - autocross Join Date: Apr 2010 Location: Camarillo, Ca Posts: 1,121	Re: Wheelbase Great info - thanks! You are right - why not do the whole thing and run new rectangular tubing which is what I have done. 65-year-old steel is not the same - twisted and soaked with oil. No Limit front and rear suspension and custom rear notch.

07-14-2021, 11:46 AM	#10
dsraven Registered User Join Date: Nov 2010 Location: calgary alberta Posts: 8,372	Re: Wheelbase Great. You can dig through the factory drawings till you find the model with the info you need for your new frame. Post up some pics if you can.

07-14-2021, 02:22 PM	#11
mr48chev Registered User Join Date: Jul 2007 Location: Toppenish, WA Posts: 15,731	Re: Wheelbase Dsraven's two photos above are a great example of the it's what your eye sees as just right that actually counts. The little difference between "that's good" and That's perfect" for some. __________________ Founding member of the too many projects, too little time and money club. My ongoing truck projects: 48 Chev 3100 that will run a 292 Six. 71 GMC 2500 that is getting a Cad 500 transplant. 77 C 30 dualie, 454, 4 speed with a 10 foot flatbed and hoist. It does the heavy work and hauls the projects around.

07-14-2021, 08:52 PM	#12
dsraven Registered User Join Date: Nov 2010 Location: calgary alberta Posts: 8,372	Re: Wheelbase on my current build I plan to run 235/60r17 tires. (its a frame swap) so the rpm will be ok at highway speeds. that's a 28" tall tire. Attached Images

07-14-2021, 09:03 PM	#13
dsraven Registered User Join Date: Nov 2010 Location: calgary alberta Posts: 8,372	Re: Wheelbase maybe helpful links. good to know stuff if doing a new suspension. like before you start the install of the new stuff. https://www.wheel-size.com/calc/?whe...cl=50mm&sr=0mm http://www.csgnetwork.com/multirpmcalc.html https://tiresize.com/comparison/ https://www.suspensiondesigner.com/k...centre-offset/ https://www.motortrend.com/how-to/in...nt-suspension/ https://www.streetmusclemag.com/feat...neering-speed/

03-28-2022, 12:10 AM	#14
hotrod1 56 - autocross Join Date: Apr 2010 Location: Camarillo, Ca Posts: 1,121	Re: Wheelbase Hey Everyone So it has been a while but got back to it. New chassis (custom) - increased the wheelbase to 114.75". The rear looks about right. The front-wheel looks a bit too far forward. There are no cab mounts on the chassis yet so it can go anywhere. Here is the bed gap spacing from the top and then from the side - which I am not sure what it should be. Thoughts? Attached Images

03-28-2022, 12:25 AM	#15
dsraven Registered User Join Date: Nov 2010 Location: calgary alberta Posts: 8,372	Re: Wheelbase personally I would move the front wheel back a bit. is that the size of tire you plan to run and the ride height of the tire in the fender is correct? just asking because the TF trucks have that angled rear front section of the fender opening so if the truck is lowered down more the tire looks like it is getting closer to the rear of the opening, and vice versa. if you want to see what the factory bed to cab spacing is google 55-59 cherolet truck factory assembly manual and pick the tri5 site. its a free download and has the drawings in there

03-28-2022, 10:49 AM	#17
dsraven Registered User Join Date: Nov 2010 Location: calgary alberta Posts: 8,372	Re: Wheelbase ok, gonna assume your chassis is done and the wheelbase is therefore roughly set with the exception of the rear axle because you have a 4 link rear suspension which can be adjusted slightly. do you have some pics of the frame without the body on top so we can see what you have to work with? if the front end is already welded in then that is not moveable but if the rear is a 4 link then that is where you will need to get your wheelbase modification from. if you have made the frame to be 114" and now you are not too sure if that was the best for the "wheel in fender look" then changing the wheelbase would be best done at the rear. I would say to install tires of the diameter you will end up with when done because the tire size makes a difference on how things looks in the wheel openings. set the suspension up at the ride height you have dialed the geometry in for during your build and pin it there with some sort of link where the shocks will mount up so it stays at that height. usually the lower control arms are level when you look at them from the front and/or the side set the frame up at the rake angle you want or you have built into the new frame when you set up the front end and welded it in set the cab and front sheet metal on and adjust them fore to aft until you get the look you want in the tire to front fender. you may need to fab up some wooden blocks the right thickness so your cab will sit the correct height off the frame since your cab mounts are not part of the picture yet set the box on at the correct dimension between the cab and nstall the rear fenders. stand back and see how you like the look of the rear wheels in the fender openings. if it isn't how you like it take a dimension on how much things will need to move to make it how you want it. the other thing you could do here, to make things the correct spacing like it would be stock, is get the original stock frame drawing out and get the dimension from the front cam mount to the box mounts and set the box at those dimensions, then do the same for the rear axle centerline. adjust the rear section of the frame accordingly or set up the 4 link bars to get that dimension as long as the C notch will allow that movement without the axle hitting the frame on a full suspension travel. it will be easier to adjust the rear frame section than it will be anything else unless you are OK with having larger gaps in the box to cab area just my thoughts, it is your truck and your plan so you gotta do what you like post up some pics of the bare frame if you can, as well as the full side of the truck if thats possible. maybe we can come up with some better ideas.



Register or Log In To remove these advertisements.

03-28-2022, 05:05 PM	#18
_Ogre Registered User Join Date: Jan 2012 Location: Motown Posts: 7,680	Re: Wheelbase did you make the frame or buy one? i have the same, 114.75" wheelbase on 58 truk do you have all the rubber mounts under the cab, i suspect your cab is tilted forward? post up a pic of the bare frame, something is not right i didn't find a good pic, but my cab/bed is closer than yours too Attached Images __________________ cool, an ogre smiley Ogre's 58 Truk build how to put your truck year and build thread into your signature shop air compressor timer

03-28-2022, 09:12 PM	#19
hotrod1 56 - autocross Join Date: Apr 2010 Location: Camarillo, Ca Posts: 1,121	Re: Wheelbase Custom chassis and the cab is just resting on it - the chassis does not have any cab mounts on it yet. Is there a wheelbase difference between a 56 and 58?

03-28-2022, 09:58 PM	#20
hotrod1 56 - autocross Join Date: Apr 2010 Location: Camarillo, Ca Posts: 1,121	Re: Wheelbase Moved the cab closer to the bed (3/4" at the top) and then place the wheel where it looks closer to what it should be - 113.5". Your thoughts? Looks like the front cross member will have to be cut out and redone - not going to be fun. I don't have any other ideas. Here are pics of the chassis. Attached Images

03-29-2022, 10:13 AM	#22
Rickysnickers Senior Member Join Date: Oct 2014 Location: Eagle, ID Posts: 3,082	Re: Wheelbase That front wheel placement looks much better. I'm sure it will be a lot of work to move it.

03-29-2022, 10:47 AM	#23
dsraven Registered User Join Date: Nov 2010 Location: calgary alberta Posts: 8,372	Re: Wheelbase I was going to say it would be easier to move the C notch ahead than to move the front cross member back, but, looking at tghe frame and all that steel in the rear, maybe not. have you mocked up/assembled the front suspension parts and placed a wheel on a hub there to see how it looks or just going by a plumb bob and tape measure? that is a heavy duty frame. what is the plan for the truck, are you putting in big power, racing?

03-29-2022, 10:56 AM	#24
dsraven Registered User Join Date: Nov 2010 Location: calgary alberta Posts: 8,372	Re: Wheelbase gotta agree the wheel placement looks better in the last pic where it is back just that little bit. did you build the frame yourself? nice skills!

03-29-2022, 01:34 PM	#25
dsraven Registered User Join Date: Nov 2010 Location: calgary alberta Posts: 8,372	Re: Wheelbase I second ogre's post about assembling the front end sheet metal and advise to assemble the suspension up front and mount a wheel/tire so you know what you have. Set the cab up on blocks of some kind to simulate the mounts and ensure everything is level with each other. Better to start at the front and work back I think, just my opinion. If you have 114" wheelbase then theoretically it should work. Like ogre says, that's what a lot of thesetrucks are running.

Register or Log In To remove these advertisements.