cohan305ci

my rear differential just went today, so im basically in need of a new one or a rebuilt one, i have an 87 z28 305 tpi with a 700R4, and im pretty sure the gear ratio was 2.73, and i figured this forum would send me in the right direction as to where i can get one

also, just a side note, if i was to run a higher gear ratio like say 3.27 or 3.75 (or 3.73) im sure id notice better acceleration, but is it even worth it to go through all the hassle of trying to correct the speedometer, maybe the computer, or anything else it would mess up (cuz i honestly have no idea, lol)

84 z28

Do you have posi or an open diff ?

Tobias05

I got my eaton posi brand new off of ebay for 380$ about a yr ago. If you go with a 3 series carrier i'd look into getting 3.42s as well. big difference in acceleration but leaves you cruising around 2200RPM at 65ish.

To correct the speedometer you're gonna need new speedo gears (forget which ones off hand, but its an easy search). One goes on the output shaft, the other goes in the speedo cable housing. You have to remove the tailshaft to get to the output shaft though, so remember that.

Also, before I forget, the eaton posi takes 28 spline axles.
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Eaton Posi