Ed Capper

[Ed Capper]

How do you tell an Eaton HO52 from HO72?

[jocko]

Hi Ed, welcome to the site. They look a lot alike - here are some good links for info. Generally speaking, if it's a corporate rear (as both the 52 and 72 are often referred to) and it came in a 3/4 ton, it's a 52 - whereas if it came in a 1 ton, it was a 72. These rears reach all the way back to 1947 in the Advanced Design truck series, but more reasonable gear ratios came in them in the 67-72 era. Anyway, check out these links, they may be able to answer your questions.

Member JBClassix did a great writeup on these here: http://67-72chevytrucks.com/vboard/s...d.php?t=536119

Here's also a great ref that member motorfist posted a few years ago, good info and rebuild part numbers, etc.
https://www.stovebolt.com/techtips/a...Ton%20Upgrade/

[Ed Capper]

Thanks. That definitely helps. It is a 3/4 Ton truck. I pulled it out of the woods near me for $300. The chassis is intact but body is totally shot. I'm doing a total frame up rebuild. I'm finding most of the parts I need but some are harder to find. I can't find any parts for the rear.

[jocko]

Yes, parts for the corporate rears are a bit scarce beyond seals and stuff like that. I think jb does a nice job outlining what 14 bolt FF stuff can transfer over.