The Stovebolt Site Forums The Shop Area Engine Shop 55Chevy Car Rear End Under 37 Truck

I'm planning on begining the installation of my 55 car rear end under my 37 truck within the next few weeks. I'll be going from a closed driveline to an open driveline, finally!

A friend tells me that I will have to reverse the rear springs in order to have the rear wheels centered in the fender opening. :confused: Can anyone verify this? If so, why?

Thanks,
Joe

22 years ago, I put a 57 Chev car rearend under my 41..the guys that were building piles of cars back then said it the perfect fit. I must admit..I never got the rear fenders put back on, but it looked pretty normal to me...I know the 37 and the 41 are a little different, but they must be pretty close too.

Joe, I'm sure this is not an issue with the 37 pickup or later pickups up to 46. The issue is the relationship of the axle to the centering bolt of the spring pack. The later trucks after 47 plus the passenger cars, had a 'pivot' that was behind this centering bolt. This made the later rear ends off center in the wheel well when swapped in. Your original 37 truck axle pivoted directly over the centering bolt so you shouldnt have a problem.

On the 57 car rear end, you probably will have to cut off the spring mounts and swap in a kit or make new, don't force the springs out to fit. I had to use lowering blocks with both axles I've used on my 46 as the original cast iron mount was taller. Have fun.

Joe, I put an open driveline in my '37, but I used '55-'59 1/2 ton components. The wheels do sit a little forward in the rear fender openings. I've heard about reversing the springs also, but when I measured mine they sure seem to be symetric. I may be wrong, but I don't think reversing them will help. Mine measure the same from the center locating bolt to each end. If you find out any more about this or try it, be sure to let us know what the results are.

6 cyl - Did you check you're measurements on that 55 rear? Seems like they are about 62" wide which will put your tire right at the fender. your 37 is probably about 58 - 60 wide. I put an S10 rear in my 39 which is about 59 wide. This gives you a little wiggle room if you put a larger tire on or if you go radial. Of course you can do things with offset rims but they can also change the look.

gaffbro -

I am currently running a 54 Chevrolet car rear axle under my truck now. It measures 61 1/4" wide and fits under the truck just fine. The 55 Chevrolet car rear end measures 59 3/4" wide, so I should be OK.

If not, I'll have a 55 Chevrolet car rear axle for sale!

Joe

Joe, unless you have to use the 55rear end why not try something else?? I used a 78-80 Malibu under my 37 and it works great. I did put some lowering blocks under the rear but the centering holes matched up..... at least on my resurrected truck!!!

You can fine tune the fore-aft placement on any rear end you use via the lowering block. If you don't want or need a lowering block, use a lets say 1" thick block, same width as springs and about 5-6" long. Get a used round head spring bolt and weld it to this 'block'so that just the head sticks out and is centered. On the flip side drill a row holes same size as round head, maybe 3/4" appart (These dimentions you can adjust as needed) first hole directly under the bolt. Then add holes away from center towards one end. Lowering blocks are inexpensive but can also be made very easily with rectangular tubing.

Now you have a method of adjusting the placement of the rear end via this little block. This item may be available through various hot rod/chassis vendors.

some where I heard that it is best to use a truck rear-end vs a car, something about more strength, but that may or may not be true,the decatur meet is in Feb,,, better get started..Fred

6cyl.

Im planning on swapping my rear in my 38 3/4 ton

let me know how it all works out for you