What is involved in changing the rear gears

[xlr8or]

A big block with 3.31 gears will be great. If you go with 3.73 in a stroked big block your first gear is going to be useless for anything but ruining tires.
With that kind of torque you don't need different gears. You want to match up the gear set to typical driving speed and make sure the final gear puts the engine at a comfortable RPM. 3.31 gear with typical OD 5th will put you around 2100-2300 at 75 MPH depending on tire size.
Here's a link to a calculator that you can play with gear selection and tire size. RICHMOND Street Performance Calculator

[fordracing65]

I did it in my spf. Gears were hard to find since my diff was from Australia not sure what diff they use now. Took forever.

[Mark IV]

Originally Posted by fordracing65

I did it in my spf. Gears were hard to find since my diff was from Australia not sure what diff they use now. Took forever.

Current diff used is a ZF, same as found in the current Camaro and the ratios are available from GM parts. The previous diff was the BTR (from Australia as used in the last gen GTO) and gears are also available from GM.

The current Camaro offers the following ratios that I can find: 3.91/3.73/3.45/3.27/2.77 so a 3.31 does not look likely but the 3.37 would b close.

[Ace23]

Originally Posted by xlr8or

A big block with 3.31 gears will be great. If you go with 3.73 in a stroked big block your first gear is going to be useless for anything but ruining tires.
With that kind of torque you don't need different gears. You want to match up the gear set to typical driving speed and make sure the final gear puts the engine at a comfortable RPM. 3.31 gear with typical OD 5th will put you around 2100-2300 at 75 MPH depending on tire size.
Here's a link to a calculator that you can play with gear selection and tire size. RICHMOND Street Performance Calculator

The 3:73 would be for my current setup until I did the big block swap in the future. I run 315/35/17's and would probably use a 3.31 with an OD 5th with a big block. My current setup turns 2700 at 70mph and that is annoying. The .64 5th would give me 2000rpm at 70mph and with the torque of a big block that would be a great cruising rpm

[1795]

Originally Posted by Ace23

The 3:73 would be for my current setup until I did the big block swap in the future. I run 315/35/17's and would probably use a 3.31 with an OD 5th with a big block. My current setup turns 2700 at 70mph and that is annoying. The .64 5th would give me 2000rpm at 70mph and with the torque of a big block that would be a great cruising rpm

I would check with your engine builder regarding how well your big block will like 2,000 rpms. Depending on the cam, it may not like it at all. With a mild cam that may be k, but an aggressive cam is going to want a higher rpm to run right.