Hey guys, I'm currently thousands of miles away from my car but am thinking about the spring project.

I have a 1971 Cutlass Supreme convertible with a 350/TH350 . i want to drop in a posi unit and bump the gears up to 3.73. I also plan on adding a 200R4 to get some oomph of the line and keep my highway driving in tact . I'm sure I'msitting with 2.72's or something close.

Are all 10 bolts the same.? What size of ring gear and posi unit should I be looking for ?

Thanks in advance.

Brent

 

They are not all the same. Some have different # of splines in the posi unit. Yours should be 28. You should have the 8.5" but they come in different sizes also.

 

Keep in mind that the 7.5" G-body axle is also a "ten bolt".