The rear end saga...

I'm turning about 2400-2600 RPMs on the interstate now, where i used to turn 2000 with the 2.73s. Hey - i'll sell the 2.73s cheap! they are in good shape. i have some 3.31s but need the 3 series carrier to install them. that's how i ended up with the 3.54s - they were in stock but the carrier was ~$60 more and a few weeks away.

with the 383, first is gone fast, hard not to spin the tires. second isn't much better! i'm hoping new rubber will fix that :)

oh - just in case it's not clear - there are two (maybe 3?) carriers, or posi units, that the gears bolt to. 2.73 and numerically lower carrier is called the 2-series, the 3.07 - 3.73 carrier is called the 3-series carrier, and i think there is a 4 series for 4.10 and higher.

Stock gears have to match the carrier; a stock GM 3.54 gear will only fit in a 3-series carrier. the problem is in the thickness of the gear. when we put the 3.31 GM gear in with the 2-series carrier, the ring and pinion didn't even touch!

I got the 3.54 gears in with my 2-series carrier by using an aftermarket gear made thicker for the 2 series carrier. i suppose i also felt better about the 3.54s with my new engine since it is a bit beefier. But be careful - some aftermarket gear manufacturers make the same ratio gear available for both carriers. the first 3.54 gear they gave me was for the 3-series carrier and it didn't fit either! that's one purchase i'm glad i made locally!