The 4:10 were only in the automatic trans trucks.
Here's a section from the Tech Tip (um, That I wrote, BTW
) that explains what donor truck to look for:
If the truck is a two-wheel drive C-20 with coil springs, 99% of the time it will have an Eaton HO52 rear axle. If it also has the automatic transmission, it probably has the desired 4.10 center section.Â
All one tons/C-30’s have a leaf spring rear. And many of those have 4.10 HO72 -- especially the big block trucks.
All Chevy k20 trucks (4-wheel drive) use leaf spring rears, and most of those will have the HO52.
Two- wheel drive leaf spring Chevy and GMC trucks 99% of the time use the Dana 60 rear axle -- these center sections will not interchange with the Eaton axles . K2500 GMC trucks use the Dana 60 also.
The 4.10 HO52/72 was standard with 350 auto trans 4x4 and 4x2 trucks and was optional on all 3/4 and one-ton trucks .
All HO52 and HO72 housings are the same, 47-72. Same axles also. Four different hubs, though: 47-70 single wheel and dual wheel hubs are different offsets; 71-72 are the same but they have 9/16 studs.
All HO52/72 rears can use any year of brakes. So a dual rear wheel rear brake system from 72 bolts in place of a 47 DRW system. Plus, almost all 14 bolt from 73-2006 brake system will work also. Wow, so you can ditch those Huck brakes at the same time ...
One last thing -- a lot of these HO52/72 rears have Detroit no spins (AKA “Lockers”). If the axle has a tag on a pinion bolt, it has a factory no spin. It will also be called out on the spid.
