Rearend question

[Harpie]

Ok so pulled the rearend out of my parts truck. It's a 12 bolt posi the old man I got it from thought it was a 373 but it did not say that on the spid. So it being a 350 auto truck c10 I figured 3.07 so before I took it out I did the ol mark the tire and turn it and count how many turns it takes to make one rotation. It was 3 1/4 with would be 3.55 so does this sound correct? I guess I just need to crack it open and take a look.
Posted via Mobile Device

[SS Tim]

Showing 3.07 as the standard ratio for that powertrain with 3.73 or 4.11 as optional. Probably a 3.07. If it is loose pulling the cover, inspecting and cleaning is always a good idea.

[Harpie]

That's what I figured it was but I will get it cleaned up and tear it all down and take a look got a set of 3.73s for it since I'll be running a 4L80E hate for it to be a dog in overdrive. And thank ya sir for the reply always enjoy your post.
Posted via Mobile Device

[DesertCat]

Originally Posted by Harpie

That's what I figured it was but I will get it cleaned up and tear it all down and take a look got a set of 3.73s for it since I'll be running a 4L80E hate for it to be a dog in overdrive. And thank ya sir for the reply always enjoy your post.
Posted via Mobile Device

Hang on a sec... if it is indeed a 3.07 Eaton unit the 3.73's won't work in it unless they are Richmond gears meant to be used in the 3 series posi.

3.73 and numerically higher use a 4 series posi unit. You might want to look into that before unpacking your new gears. Good luck!