[b-man]

1967 GTO with A/C and auto trans had a 2.93 rear end.

I’d be looking at replacing the 8.2 10-bolt rear with something more robust anyway if you’re planning to actually use all 400 horsepower rather than baby it. Don’t make the same mistake that most guys do by adding horsepower and neglecting to consider the strength of the rest of the drivetrain. The 8.2 10-bolts that came in all the 389 and 400 GTOs are notoriously weak, plenty were broken and replaced under warranty when these cars were new.

Either way additional cubic inches are your friend when tugging a 2-series rear gear.