Rear differential suggestions

[Missyblue]

I'm need of advice I'm drowning in articles and build threads haha new to this world and learning slowly......
I have a 56 planning to use a 350v8 from a donor vehicle and 700r4 tranny want to go automatic and looking for daily driver with preference being on better gas mileage than hot rod offf the line. Max speeds usually around 60 mph. Hoping to find a donor differential that won't need too much modification due to its width or lugs I have seen the lists of some that fit but hoping for advice on things that work well and gear ratio arguments. 1 mechanic I talked to recommended 3.73 but curious. We prefer to stay with chevy/gmc but woukd consider others. I know Ford 9" are recommended and someone said dodge dakots.....
Hoping to start searching and watching. Not in a huge hurry as I'm in savings mode and need to find a good deal
Thanks for the advice this place is awesome

[nail pounder]

https://www.ringpinion.com/calculators/Calc_RPM.aspx

Use this link. I have a 350/700R4, 235/75/15 tires (28.5) with the stock 3.90 in my 1958 and it's fine, cruises 70mph about 2200rpm, and roasts the tires easily. 3.73 is a good all around ratio as well.

[roger55]

I've got a '65 GMC pickup rear housing in my '57 3200 pickup. GMC pickups used Dana 44 rears.

The width is perfect. 2 minor mods have to be made. The spring perches were off just a little bit requiring them to be cut off, moved and re-welded. Have modify the rear e-brake cable too.

I had mine rebuilt with new 3.54 gears and a trac-loc (posi) unit.

Mid to late 60's Chevy pickup rear should work width wise and parts are available for those too.

[Driver_WT]

You can also use the rear axle from a 1996 to 2001 Ford Explorer, try to get 3.73 gears and limited slip. You may need to move the spring perches a bit and redrill the wheel bolt pattern in the axle end plates, but you will have a strong rear axle.

[Missyblue]

Thanks for the advice! I'll definitely check out the calculator....
Roger55 sorry if this is a silly question but what is the reasoning for a 60' s rear over the original if they can alter great ratios?? Easier to find parts or can the original not be geared the right way?
Driver_WT I have only spoken to one build guy in my town, have several others to interview,
so far but he encouraged me to stay away from suv rear ends saying he finds them more problematic and week. But you have good luck with the Ford?? I understand their are thousands of opinions so curious of your experience....
Thankjs again!

[Driver_WT]

Originally Posted by Missyblue

Thanks for the advice! I'll definitely check out the calculator....
Roger55 sorry if this is a silly question but what is the reasoning for a 60' s rear over the original if they can alter great ratios?? Easier to find parts or can the original not be geared the right way?
Driver_WT I have only spoken to one build guy in my town, have several others to interview,
so far but he encouraged me to stay away from suv rear ends saying he finds them more problematic and week. But you have good luck with the Ford?? I understand their are thousands of opinions so curious of your experience....
Thankjs again!

I currently have a rear end from a 1995 S10 in my truck. It is not strong enough to handle the torque of my engine. I am on the hunt for a Ford Explorer 8.8 rear end with 3.73 gears for added strength. If you want more info on this, Google "Ford 8.8 rear end for Chevy S10) and you will see that many Chevy owners have installed an 8.8 rear end in their Chevy trucks. The Ford 8.8 rear end was used in many Ford vehicles and it is a strong and reliable piece. I have one in another project vehicle and it works great. I am recommending one from a 1996 to 2001 Explorer because it is the right width for a 1953 Chevy truck.

[roger55]

Originally Posted by Missyblue

Thanks for the advice! I'll definitely check out the calculator....
Roger55 sorry if this is a silly question but what is the reasoning for a 60' s rear over the original if they can alter great ratios?? Easier to find parts or can the original not be geared the right way?
Driver_WT I have only spoken to one build guy in my town, have several others to interview,
so far but he encouraged me to stay away from suv rear ends saying he finds them more problematic and week. But you have good luck with the Ford?? I understand their are thousands of opinions so curious of your experience....
Thankjs again!

Parts for the originals are limited and expensive.
I think there's only like 2 ratios available for them as well. No posi units for them at all. They just aren't worth putting money into.
Both the GMC Dana 44 and Chevy rears from the '60s have all parts available, many ratios to choose from, posi units available and prices are reasonable.

[nail pounder]

Originally Posted by roger55

Parts for the originals are limited and expensive.
I think there's only like 2 ratios available for them as well. No posi units for them at all. They just aren't worth putting money into.
Both the GMC Dana 44 and Chevy rears from the '60s have all parts available, many ratios to choose from, posi units available and prices are reasonable.

I think you're right, if I remember correctly the original rear can be 3.90 or 3.38 but those are readily available. I've seen the original rears for cheap and sometimes free, might be a budget friendly option for a daily. As you said, I wouldn't dump a ton of money into an original and a Ford 9" or Dana is much better for performance. I kept my original because it functions fine, I wanted 6 lugs and suits my needs, for now anyways.

[Missyblue]

I have my original not sure how it functions until we get going so was just curious. I thought they were recommending a different differential for performance since the original truck wasn't meant for today's speeds and power we have gotten used to.
Nail pounder what power plant are you running in yours?
So if I did the 8.8 ford it seems they have disk brakes on the years suggested above the 96-01 so if I upgraded my master cylinder I could keep those? that would be a nice upgrade. Have to convince my husband he's one of those silly fix or repair daily negative Ford guys but this is my dad's and my truck and we are a love of all trucks family haha
Thanks again I appreciate it
For clarification my mechanic said I'm looking for a 60" rear but in the specs it says my 57 is a 62......what width wiggle room do I have for keeping this easier to install as I search for options around here

[roger55]

The aftermarket only 3.38 gear set is a nice ratio but a new set will cost about double of what gears for the other rears talked about here would cost.

[nail pounder]

Originally Posted by Missyblue

I have my original not sure how it functions until we get going so was just curious. I thought they were recommending a different differential for performance since the original truck wasn't meant for today's speeds and power we have gotten used to.
Nail pounder what power plant are you running in yours?
So if I did the 8.8 ford it seems they have disk brakes on the years suggested above the 96-01 so if I upgraded my master cylinder I could keep those? that would be a nice upgrade. Have to convince my husband he's one of those silly fix or repair daily negative Ford guys but this is my dad's and my truck and we are a love of all trucks family haha
Thanks again I appreciate it
For clarification my mechanic said I'm looking for a 60" rear but in the specs it says my 57 is a 62......what width wiggle room do I have for keeping this easier to install as I search for options around here

I have a 350 and 700R4 with stock rear. I am/was in a similar situation as you. I want a good daily driver, not a street rod and I'm on a budget. Mine does great on the freeway with overdrive trans, and is still quick off the line. I may upgrade the rear end in the future but I did the motor swap a year ago see no need for a rear end at this time. I changed the diff fluid a couple times and now it's quiet and smooth.

[Jemezcrusher]

Originally Posted by Missyblue

I'm need of advice I'm drowning in articles and build threads haha new to this world and learning slowly......
I have a 56 planning to use a 350v8 from a donor vehicle and 700r4 tranny want to go automatic and looking for daily driver with preference being on better gas mileage than hot rod offf the line. Max speeds usually around 60 mph. Hoping to find a donor differential that won't need too much modification due to its width or lugs I have seen the lists of some that fit but hoping for advice on things that work well and gear ratio arguments. 1 mechanic I talked to recommended 3.73 but curious. We prefer to stay with chevy/gmc but woukd consider others. I know Ford 9" are recommended and someone said dodge dakots.....
Hoping to start searching and watching. Not in a huge hurry as I'm in savings mode and need to find a good deal
Thanks for the advice this place is awesome

Go to the u pull it and get a 8.8 inch from an explorer or mountaineer. I think 2000 model up until they went to independant has disc brakes. They came in 3.55 and 3.73 in the 4x4 models and the ones I have pulled have tags. I have 3.73 in both. Good cruising with my 700R, and should be able to get 70 MPH with my 5 speed and 235 six n the truck These are very strong. I have on in my 55 Chevy sedan and in the 50 AD I am working on. Strong, cheap

[Trucknut57]

In my 57' I have a 350 SBC and a turbo 350 transmission. I installed a 1972 Camaro rear axle that has 2.73 gears. Now it may not smoke the tires in every gear but it gets almost 18mpg with this setup.
With using the camaro rear axle I found out it was narrower than the original rear axle, which allowed me to use some wider wheels and install rear disc brakes from a 2000 blazer.

So in my application it works great.

[Missyblue]

Awesome thanks for sharing......we don't have very good salvage options here so might have to travel. I know things are regional but what would you say is possibly a reasonable price range for the ford 8.8 that you have seen? Or the older camaro/truck stuff from the 60's? We are secluded so prices get rough around here . I remember Arizona had a good selection of u pull it places might have to make a trip only 10 hours away.
Also what else do you or would you change/upgrade in the rears? New leaf springs or shocks? that kind of thing?

Then if doing the Ford and disk brakes would you just do a bolt on disk kit for the front or would you do a front clip? Or can I just keep my drums for now and upgrade my master cylinder?
Thank

[Driver_WT]

Originally Posted by Missyblue

Awesome thanks for sharing......we don't have very good salvage options here so might have to travel. I know things are regional but what would you say is possibly a reasonable price range for the ford 8.8 that you have seen? Or the older camaro/truck stuff from the 60's? We are secluded so prices get rough around here . I remember Arizona had a good selection of u pull it places might have to make a trip only 10 hours away.
Also what else do you or would you change/upgrade in the rears? New leaf springs or shocks? that kind of thing?

Then if doing the Ford and disk brakes would you just do a bolt on disk kit for the front or would you do a front clip? Or can I just keep my drums for now and upgrade my master cylinder?
Thank

I am currently near Ft Myers in Florida - U pull price for Ford 8.8 is around $100. There are also at least 4 Ford Explorers on local Craigslist that are being parted out. I would expect to pay $100 to $250 for Ford 8.8.

[Missyblue]

Awesome thanks for the info.

[Trucknut57]

I need to correct myself on the camaro axle width. The camaro width is 62.50" and the original axle width is 62". So you would be getting a 1/4" wider on each side.

Some people will keep their straight front axle (I still have the straight axle) but most will swap out to some other type of independent front suspension. Only you can make that choice.
If you keep the straight axle and upgrade (I strongly suggest you should) to front discs, most of those kits use the 70-81 Camaro rotors and calipers. On the plus side, If you go to front discs and use the camaro rear axle the bolt patterns will match, 5 x 4.75".

Good luck with which ever direction you choose to go.

[Trucknut57]

I believe that is the same kit I used. Goes on easy, just make sure your king pins are good and change out the master cylinder for front disc / rear drum.

[nail pounder]

I have power drums on my 66 and they work great. I'd make a necessity, priority and want list and start there. My 58 is a work in progress, I did 6 lug disks up front, Sid's 3" drop axel, new king pins, tie rods etc. It drives fine, not like a new vehicle though. If you're looking for the new car ride, IFS is a the way to go. Anyhow, post up some pics!

[Missyblue]

Here she is. My daughter called her missy blue and it stuck. It's a father daughter granddaughter project. Grew up in a 56 and we lost it throughout the rough times. I got this 57 kind of as a suprise last summer and thats the photo the day it came home on the trailer. And now we are saving and getting to work rebuilding something for us again. They painted it an original orbit blue which is cool. Definitely not a show job but it works for now. Happy that it has a pretty clean body overall and now getting to work just hoping to get my dad driving one again. He doesnt have money for it so it's all me. Just putting together all the pieces and resesrching the rest Loving the memories and fun. Lots to learn for sure and so thankful for this place

[Missyblue]

I think our trucks match colors nail pounder
It looks like you are making great progress on the underside. And thanks for the advice. Definitely making lists and priorities

[nail pounder]

Originally Posted by Missyblue

Here she is. My daughter called her missy blue and it stuck. It's a father daughter granddaughter project. Grew up in a 56 and we lost it throughout the rough times. I got this 57 kind of as a suprise last summer and thats the photo the day it came home on the trailer. And now we are saving and getting to work rebuilding something for us again. They painted it an original orbit blue which is cool. Definitely not a show job but it works for now. Happy that it has a pretty clean body overall and now getting to work just hoping to get my dad driving one again. He doesnt have money for it so it's all me. Just putting together all the pieces and resesrching the rest Loving the memories and fun. Lots to learn for sure and so thankful for this place

Nice looking truck! I'd say drop a motor and overdrive trans(700r4) in it, leave the original rear end, fix the existing brakes and drive it. Then tackle your list as money allows. They are more motivating to work on if you can take it out for a drive once in a while.

[whitedog76]

Originally Posted by nail pounder

Nice looking truck! I'd say drop a motor and overdrive trans(700r4) in it, leave the original rear end, fix the existing brakes and drive it. Then tackle your list as money allows. They are more motivating to work on if you can take it out for a drive once in a while.

I like this advice.

I had all kinds of ideas when I bought my 54. Tore into it. Made a mess. Well and I still have a mess.

I wish I would've just got her running and worked things out from there.

[Missyblue]

Thanks for the advice. Yeah my husband thinks I'm nuts and should do it right as a frame off but then I know I'll never drive it so that's why I'm here pestering you guys for advice. I don't have lots of money and so trying to do it the "right" way for us and get it running affordably. But also doing my research because if I can do something like get a Ford rear end with disc brakes for less than updating my brakes later that might be the way to go so trying to be smart about some of those decisions. Im working on my priority list and will keep all your advice for options. But at this point getting on the road and safety are number 1 and then upgrades for comfort are later like you say.

[1project2many]

You've probably already realized there are a *lot* of excellent builds and very talented people on this forum that are willing to help out. It looks like your questions have changed from advice about the rear axle ratio to advice about a direction to go with your project? I'm usually in the minority here because I prefer a more practical and less expensive approach to building a good truck but I'll share my perspective.

Truck projects can take much longer than expected. Mine was already on the road and running when I started the body work. Three years passed before it drove out of the shop. For cost and simplicity I left mine mostly stock. It still has drum brakes, still has the stock rear axle and transmission, no air conditioning, and the original manual steering as well. I even left the same brake shoes and shock absorbers on the truck that were there when I bought it. Most of the folks on this forum wouldn't keep their truck at this basic level but I've been using mine since '98 and enjoying it the whole time. And despite what I seem to see on the forum most of the parts on the truck are capable of surviving well in daily use.

With your truck already painted it would seem like any changes or upgrades should be planned so bodywork and paint isn't touched. I don't disagree with the safety concerns over the original single chamber brake system. The master cylinder is underneath the floor of the truck and there are kits available to put a modern dual master cylinder with brake booster under the floor. The original brakes do require some effort to use and if you mostly drive a vehicle with power brakes the manual system will seem like it's fighting you as your driving day gets longer. If you replace the drums with discs you're probably heading for a replacement master anyway to make the brake balance work out. I'm happy with the drums on mine but I am going to add a '60s vintage brake booster in order to get power assist.
Edit: The early Chevy vans also used beam style axles. This disc brake swap seems well documented by someone with good experience: http://www.angelfire.com/wv/joyrde/v...scBrakes1.html


The factory steering parts were designed to work with skinny, stiff, bias ply tires. Switching to modern radials requires a lot more force applied through the components and you may find driving to be tougher than expected. My truck didn't seem tough to drive when I was in Montana where we had wide roads and little traffic. But back east people drive very agressively. Stop lights here are sometimes only a couple hundred feet apart and there are plenty of folks racing to be the first person to stop at the next light. Plus many of the roads here are in pretty rough shape. Driving with these folks is a bit more challenging. Since I'm not getting any younger so I have plans to improve the steering components and possibly to add power steering to the old solid axle. Like your truck, the body work on mine is done so any changes I make will not involve redoing the body.

An automatic transmission is a great idea. And I agree that keeping a shifter out of the center of the truck makes riding with a child in the center much easier. '55-'59 GMC and Chevy trucks came with automatic transmissions so there are column shifters that bolted directly to the original column. They are likely to be tough to find and expensive but I wonder if it would be relatively easy for a creative person to build something similar or to modify a 3 speed shifter for the original column. Most folks end up adapting a later column instead of working with the original part. Since the original box and column don't easily separate the original column and the steering shaft will need to be cut and and modified to connect with the later column. Many folks seem to buy a column from a RWD car but I wonder if a later FWD column might be a good choice. The FWD columns are shorter which might allow the original column to be cut inside the cab of the truck. The FWD car columns also use a cable between the transmission and column which might be easier to adapt to the automatic than building linkage.

My real lament is that there's no room in the cab of the truck. For years it was only my wife and myself and we could bring a small cooler and a bag when we went on long trips. Once my son came around it was much tougher. And with two kids there's no way everyone can go out for a drive. If you are looking at making any changes inside the cab I'd recommend trying to incorporate more storage space.

Good luck!