So... was lead to believe the rear end in this thing would be a 2.72:1. Checked and it is 3.07:1. 40 tooth crown and 13 tooth pinion. That sound right? How is a 3:07 for a street gear? 8.2 10 bolt bop. Also has numbers 455 stamped on bearing caps if that means anything.

 

maybe 3.08 actually.

 

3.08 was the standard gear for 1966 cutlass with a/c

 

b I would sell a ton of 2.93 3.08 3.23 IF the gears were available. JUST a good all around ratio for everything.
Trouble is most people get bigger duration camshafts and think they are improving low end because the car has MORE HP...that is not so in a way...
usually bigger cams have for duration making the power /torque band move up the rpm scale and then you loose the idle to 2500 torque range all muscle cars are known for.
so then the band aiding starts... more gear ratio needed...more torque converter stall needed... re-curving the distributor to advance soon cause worse fuel mileage ...
So if your engine is stock and you bump the ratio it is going to be very noticeable torque improvement.
455 is a BUICK casting rear end.
Pontiac would have < and > symbols on the caps
WHAT is your motor? How is it built? What are you going to do with your car? These will help you answer your question.
I can tell you they are harder to come by... they are on a 3 series carrier which holds only the 2.93 3.08 and 3.23 gear sets.
If you want 3.36 3.55 3.90 4.33 ratios you will need to step up to the next carrier which is more popular in the aftermarket...all those are available NEW including the posi etc.
Jim
JD RAce

 

I am thinking a 3.55 gear. Am installing a th350 and rebuilding the 330 but am looking for something that is a great mid rpm ripper. Just for rippin around the town from time to time. Where does a guy go looking for a 3.55 posi? For a buick 8.2 10 bolt then?