[SWHEATON]

I HAVE A 12 BOLT POSI IN MY 69 CHEVELLE THAT HAS THE OPT 3.07 (NOT 3.08) RING & PINION
and have a gear change question.

1) Which carrier does the optional 3.07 gear in a 12 bolt posi use,series 2 or 3?

2) Which carrier does the 3.31 gear in a 12 bolt posi use,series 2 or 3? (I think series 3?)

3) Are the 3.31 ring & pinion gear sets the same in 65,70,and 71? Or is there a defference in the pinion shaft size/diameter or ring gears through the yrs?

4) Last of all,will a series 3 carier from a 71 12 bolt posi fit my 69 12 bolt posi housing? (I Would think so but not sure)

Thanks a lot for answering my questions.

Scott

 

[big gear head]

Scott, the 3.07 and 3.31 both use the 3 series differential. The gears are all the same from '65 to '72, as long as they are car gears. The 12 bolt truck gears are different. All of the parts from the car 12 bolt from '65 to '72 can be interchanged, with the only difference being axle length. The Impala has larger axle bearings.

 

[SWHEATON]

BigGearhead,thanks a lot for your answers to my 12 bolt questions. I have noticed over time reading many posts here in T/C that you know a lot about the 12 bolt rears and i value/appreciate you taking the time to help me out & set me straight.

But i do have another question,is the Elcamino considered a truck 12 bolt posi or a std car 12 bolt posi.

Thanks again from a fellow T/C'r.

Scott

 

[big gear head]

The El Camino is built on the Chevelle platform and has the Chevelle 12 bolt rear end.