The Stovebolt Site Forums The Shop Area Engine Shop 3/4 ton rear end.

If I get a 3rd member from a 67-72 3/4 ton to put in a 52 can I be reasonably certain it will be 4.11 or even possibly a 3.90. Thanks George

George,

I have no additional data to confirm the accuracy of this vendor's info, but here are the axle codes for the 67 and 68 Chevy trucks. Should help to guide you in your search.

http://www.gmcpauls.com/67-72_chevy.htm

No. Just as likely to be a 4.57. It's real easy to tell the ratio by jacking up a tire and spinning the wheel and counting the wheel turn to drive shaft turn, then getting the ratio. You don't have to be dead on. It'll either be 5.13 (not original to that year and model) 4.57 or 4.11. Destiny is never so nice that it would be a 3.90.

There were no 3.90's made for the 3/4 ton Eaton axle. There were a very, very few models that had a 4.11. Been lookin' for over a year and haven't had one single bite.
Where there is a demand there should be a supplier. I can't for the life of me figure out why one of the gear grinders hasn't set up for one that will fit the 3600 AD's. I don't know anyone that has a 3/4 ton that doesn't want to go with a higher gear than the 4.57. Oh, maybe there are a couple but that would be 1 out of 10,000.
Good luck!
Denny Graham
Sandwich, IL

The rearend gears that you want are 4.10 and if you count the teeth on the ring, there are 41. The description that I hear over and over is 67 to 72 3/4 Ton with automatic and coil springs. The reason for mention of coil springs is because there were some Danas used with the leaf spring setup. I put one from a 71 in my 51 1 Ton and it cruises nicely at 50 mph, which is what I want with my original 216.

Denny, looks like you're going to have to break down and upgrade to something more modern if you want to run cruise at 55/65 mph.

Nope Jim, the only thing more modern that’s goin in my rear end is a gear. I’m not changing the housing. I know they are out there I just have to find one. Of course by the time I find one I could be so old that I won't want to drive over 45-mph. With a stock 216 I doubt if it could pull anything higher than a 4.10. And I stand corrected Fred, your absolutely right on the ratio, force of habit from the old drag race days you know.
I see where some of the guys have gone on a nation wide search to find one. I just hate to think about going to all the trouble of having a carrier shipped from Oregon to Chicago and finding out when it gets here that it's not the right one or that the gear set is shot.
Denny Graham
Sandwich, IL

Thanks for the help fellow bolters. I know what to look for now. My partner has a salvage lot. He is going to get one this weekend. Denny, if he has more then one would you be interested in one? George