The Stovebolt Site Forums The Shop Area Engine Shop 53 chevy 3100 rearend question

since Im sure alot of you guys have already done a rearend swap on youur 1/2 ton, can you point me in the direction i should be looking, i wanna swap out the rear and torque tube, never done anything like that before and wanna get a good gear ratio for highway driving with out alot of engineering taking place, not sure if 235 or 292 is going in yet, but i do have a saginaw 4spd(2 grooves), any help would be appreciated.

This question comes up often. The search feature will turn up hours of reading on the subject.
Plan on relocating the spring pads on whatever rear you choose, if you don't do a '55 to '62 pumpkin swap.
What gear ratio do you want?
Do you want to stay with 6 lug or convert to 5?

The first combination we ran in "Walter" was an open rear end from a full size '78 Blazer with 3.08 gears and a Saginaw 4 speed. Our Saginaw was a 3 groove so it had the 3.5 first gear but the 2 groove with the 3.11 first is probably better with closer gear spacing. We ran 235/70 15 rear tires and it was a great combination with the 261 engine. We chose the '78 Blazer because the width was almost perfect and it had 6 lug axles so we could keep matching rims front to rear. As Ghostrider said, you'll have to relocate your spring pads.

thanks for the info, i checked out your truck when i bought mine, i tried hard to find a 261 but no luck, this week i found a place where the guy has a pile of 55-62 235's, it seems that the you can squeeze some torque and hp out of the 235, so i think im gonna pick oneup this week(175.00).

Arpee, was the 78 blazer you used a 4 wheel drive? I heard that only 4 wheel drive blazers from that year had the 6 lug bolt patterns

Yes, it would have had to come out of a 4x4, 2wd Blazers were 5 lug. It wouldn't necesarily have to come out of a Blazer, Suburban 4x4 or K10 pickups have the same axle. If you can find a '76, it will be a 12 bolt, '77 and later are 10 bolt.

Thanks. this weekend I came across a axle, driveshaft, and transmission from a 1958 1/2 ton for sale. I'm looking to find a replacement for my 1953 3100 which has the torque tube. Ghostrider mentions a pumpkin swap for years 55-62. Does that mean its a direct bolt in replacement and the spring pads won't have to be relocated? The only problem is that its a 3:91 which is a slight improvement over the 4:10 I currently have. If I bolt a saginaw 4speed to this, will I be able to cruise at 65 mph or will I need to go with something in the 3:55 range

The 55-62 pumpkin is a bolt in but you have to weld up the pivots at the spring mountings. Its true the 390 wont be much improvement in ratio but you will have the open drive shaft. You will need the 3.38 gear set or o-drive trans.