55.2-59 C4 vs Crown Vic

[jaws61]

Hi guys
What everyone's thoughts on what's best to do.. I'm building a 58 Chevy truck with a 2017 mustang IRS rear end..

Just trying to make the what would be better, I'm thinking more a autotrack truck..that really handles..

Run a c4 with flat out engineering cross member and than two different bolt pattern wheels

or

Run a 2003-11 Crown Vic front suspension stock and than use 2018 Mustang wheels which end up with a 74 inch wide from tire to tire... Than I end up same bolt pattern wheels

Or 03-11 Crown Vic front with a team 321 one cross member.. makes the wheels track width right.. buy a set of wheels..

I've yet to buy a set of wheels... The trucks going to run a 6.0 ls engine and custom.chassis...

Thanks

[mr48chev]

Everything I have seen with Crown Vic suspension has the wheels out way too wide for the vehicle. Then you have to use real ugly wheels to get them close to fitting under the fenders.

Your call, do you want to run ugly wheels so you can use a cheap worn out cop car suspension ?

The first Crown vic install I saw was in a 60's F100 with a 4BT diesel in it. He had a real issue with the wheel fitment with it.

They work if you have a 70 something F100 or F150 that you want to make low but if you get away from The F series fords you have to do some cobbling to get them to fit most anythign else.

[jaws61]

Thanks for the opinion and if anyone got a thought let me know too..
I'm also curious what is most trucks outside wheel width.. from tire to tire...so could use it to compare to what I got...
Thanks

[jaws61]

Thanks for the opinion and if anyone got a thought let me know too..
I'm also curious what is most trucks outside wheel width.. from tire to tire...so could use it to compare to what I got...
Thanks

[joedoh]

how committed are you to autotrack? (I think we call it autocross here in the states, interesting aside)

because a top heavy all steel truck with 70/30 or 65/35 weight distribution on a ladder frame is going to be terrible at autocross without a lot of money in motor placement and suspension balance.

I have a friend with a C4 front rear swap on a 55 and it rides and handles great, but it would lose every autocross it entered. the newest c4 is 25 years old! crown vics are popular right now but I dont see guys doing it for autocross. I have a 1998 grand marquis I have been contemplating putting under my 56, but it wouldnt be a handling thing for me either.

[jaws61]

I'm not that committed to autocross but more just to take it on a track to have a fun time and go around the track, I'm not going to race or win just want a fun truck to have a good time with... My last truck has a M2 it was nice but not that sporty of a drive...

That's nice you buddy got a c4 in his truck and handles great...

I.agree the c4 nice but it's 25 plus years old and I'm looking at a 89 suspension.. that why I'm.curiois If there would be a improvement to go with a Crown Vic that's 03 suspension tech which is 14 years newer...

I want a fun sporty truck really but really at the end of the day it's gotta down the road.. going to measures out my wheels to get a better idea tomorrow..

Crown Vic just so cheap stock to run but c4 better deal if gotta move crossmember...
I can get a c4 front for $400 Canada buck which is a deal I think..

Any more thoughts great or wheel measurement thanks..appreciate the thoughts and opinions..

[dsraven]

58 Chevy truck with a 2017 mustang IRS rear end
The trucks going to run a 6.0 ls engine and custom chassis.
ok, let me get this straight:
you wanna put a different rear suspension under it, will run a custom chassis and obviously a different type of front suspension.
you want to go around corners fast but won't be racing against anyone but yourself really, for fun.
please explain what you mean by a custom chassis. if you mean you will cut the old frame behind the cab to accommodate a different unit from a different car, then cut the old frame ahead of the cab and install some sort of IFS up front, then in that case your "custom chassis" idea is really only going to be using that center section of frame to mount the cab and there will be multiple areas in which to mess up the chassis being square and true plus a lot of welding to the frame length just to install different suspension parts on each end. you will likely be removing cross members along the way even in the middle section in order to make drivelines work since I assume you want the old truck to sit as low as a newer style "donor" muscle car. maybe an idea to consider would be to start with deciding what you want and then start from scratch building a new frame to accommodate the suspension choices you have made. really, these frames are pretty flat, front to rear, with a small kick up over the rear axle and some tapering out front. you could fab your own frame using the GM dimensions from the assembly manual drawings. then you could use box tubing, to eliminate the need to spend time and money boxing the old frame, all the steel would be new and not prestressed from years of work, no unrequired frame holes to spend time welding closed, etc etc. it may be worth your time to research a few manufacturers and see how they have built their frames and then come up with a plan for yours.
I did a quick google and found this
Crown Vic front suspension track width is about 67″ wide as measured from hub / hub. this is not wheel to wheel, hub to hub.

not sure if these guys are still around but they make a narrow crown vic cross member
https://team321.com/slider/narrow-cr...t-crossmember/

they also use a ford rear IFS and have the install do it yourself on a 50's era ford here
https://team321.com/truckirs-installation-page/
these guys use corvette underpinnings. they use laser cut frame parts that are welded together on a frame bench to form the channel. nice stuff as far as I have seen in person.
https://www.canadianhotrodsinc.com/frames-chassis/

https://totalcostinvolved.com/produc...-rear-chassis/

https://artmorrison.com/products/gt-...55-59chevtruck

https://www.scottshotrods.com/1955-5...truck-chassis/

https://www.fatmanfab.com/product/19...-truck-chassis

https://roadstershop.com/product/ful...truck-chassis/

https://www.schwartzperformance.com/...truck-chassis/

https://www.gsimfab.com/1955-1959-ch...4286_8863.html

more corvette stuff
https://www.progressiveautomotive.co...short-bed.html

https://www.peteandjakes.com/new-195...truck-chassis/

https://nolimit.net/

https://pbfab.com/

lots of parts available here
https://welderseries.com/?_vsrefdom=...kaAv2iEALw_wcB

you maybe want to download a copy of this for future reference
https://www.trifive.com/d1/55-59Assy.pdf

this site gives gm drawings of newer trucks in case you want to see track widths etc
https://www.gmupfitter.com/pages/body-builder-manuals

here is a link to a thread on here that uses a crown vic on an AD truck. a few challenges including width, which was overcome by narrowing the cross member. really do some research on IFS geometry before you pull the trigger on anything
http://67-72chevytrucks.com/vboard/s...ight=crown+vic

then there is the jag front and rear suspensions that have been used in trucks since they are narrower. here is what they look like, or google it if it interests you
https://www.kwecars.com/jaguar-upgra...grade-renewal/

https://www.hotrod.com/articles/inde...nt-suspension/

here is a site that will give wheel offset comparisons and how that will affect scrub angles etc
https://www.wheel-size.com/calc/?whe...cl=50mm&sr=0mm

https://www.racingaspirations.com/scrub-radius/

https://www.car-engineer.com/suspens...icle-behavior/

these guys cover a lot of the suspension theory as well. they have different tabs you can click on. really consider your wants/needs and compare with different set ups before pulling the trigger on something. that will give you the best results
https://suspensionsecrets.co.uk/anti...lift-geometry/

that should give you some ideas to look at. think about/research what you want/need for frame rigidity for the purpose you want and how that will affect the day to day ride. personally I am not partial to a hard ride every day just to go cornering once in awhile. a harsh ride tends to make you clean, polish and tinker more than drive because it is simply not comfy. lots of potential riders will also find an excuse not to be available for road trips as well. to each their own though.
how much suspension travel you want/need, what you want/need for brake rotor diameter and cooling as this will affect wheel choices, what you want/need for tire choices as this will affect the frame width at the rear. where you want/need your brake booster to mount and will it be vacuum or hydraulic. where will you place the fuel tank as this heavy item can affect the front to rear bias. if thinking of short control arms due to a wide original track width from a donor also think of how that affects suspension travel and handling etc. even a simple thing like a tire size change without considering the geometry changes that come with can really change how the vehicle handles on a track/handling scenario.

[mongocanfly]

Mines not on the road, but I have a flatout kit and a vett front on a pallet in my shop..
The quality of the flatout is extraordinary..it looks great...

[dsraven]

hey jaws, any answers floating around? thinking?

[jaws61]

Thanks dsraven huge help...
I've been reading through all the great information.. thanks alot, I am planning to use a full custom chassis... I put up the Crown Vic front end as if was going to on the truck... The front was way way to wide and looked way out of place...a monster truck style... Plus is 36 inches between the rails and not 34 like I've read...

In the end I got a first gen c4 front suspension and I'm going to run a flat out kit... I wanted 88-96 style but I'm more than happy I got something for right now and I'll keep a eye out second one.. I'm also going to read more if there any geometry or advantages over the early and late c4 , which I'm going to run a c5 for brakes..
The weight difference from the front end is huge..and the width is right on..

I also used a bunch of ideas on how to make my inner frame stiffener from the links too..and been doing a bunch of reading. And learning so thanks...