The Stovebolt Site Forums The Shop Area Driveline 3.90 gear into a 53 1/2 ton

I’ve done some searching but haven’t found definitive answers to my questions.
Here are my thoughts:
Truck ‘53 1/2 GMC/Chevrolet with stock torque tube 4.10 rear

Donor gear. 62- 3.90 1/2 ton.

I will be installing a 261 with a T5 and wanted the open drivleine.

I’ve read that this will bolt right in, so no worries there. But I want to use the backing plates from the 62 as parts (from what I’ve seen) are cheaper.

The 53 is Bendix, so is the 62, correct?

Are the drums from 53 the same as 62?

Are the axles from 62 the same as 53? Spline count? Length? Etc? I have some broken lug studs and wonder what else I may find damaged on the 53’s axles.

I know I will have to weld the spring pivots, but has anyone built a “saddle block” instead and repositioned the rear to better center it? If so, how did you do it? That rear end being offset in the rear fenders drives me nuts in these trucks. And yes, I understand how the torque tube requires this offset but it still bugs me.

If I use the 62 backing plates, this may affect parking brake configurations (they are different). So if you’ve done this, or simply used a 62 rear, how did you overcome the park brake dilemma?

The reason why I didn’t simply bolt in my 62 rear end is because the main tubes were severely corroded to the point of making me nervous.

Thanks Bolters.

1962 brake parts might be cheaper, but are they cheap enough to justify the work involved in changing backing plates and reconfiguring your parking brake?

I swapped a 1961 3.90 center section into the rear end of my 1953 GMC half ton. I installed a T5 using an adapter from Hamilton Intakes and centered the rear axle in the fender openings.

The center section swap is easy. The axel spline count is the same. You'll have to do a little grinding on the ankle housing to make clearance for the taller ring gear when installing it.

To center the axle in the fender I cut a couple small plates out of quarter inch steel and drilled 2 holes in each plate about an inch and a half apart. One hole was drilled large enough for the axle to spring alignment pin. The other hole was threaded to accept a short Allen head bolt with a head the same size as the alignment pin. It would make it easier to understand if I could show you a picture of it but I've just moved and all my pictures on my computer which is in a box in the basement right now.

With the T5 and re located rear end I was able to use a stock Astro Van drive shaft.