[MUSLCAH]

My AC 1967 GTO TH 400 …has a 3:23 posi

[4zpeed]

Originally Posted by MUSLCAH

My AC 1967 GTO TH 400 …has a 3:23 posi

I use 3.23's with the early Muncie 2.56 gear set but everyone has to decide what works best for them, an all around nice gear regardless.

Originally Posted by will slow gto

My favorite event to follow is the PSMCDs - I’d love to participate but I’m 2500 miles away. Sounds like some improvements can be made to the exhaust and still be considered stock.

If your car is stock it has a factory 2" exhaust system which was standard for auto equipped cars.

The manual transmission cars were equipped with a 2-1/4" system, the manifold was the same.

This could be a viable option to enhance exhaust performance and still be considered stock.




Frank

[dataway]

3.23 is a great gear I think for street driven GTOs, very noticeable performance increase over the 2.93 a very little perceptible increase in RPM.

Anyway ... for my "stock" automatic GTO I used stock logs with the ports cleaned up and the outlet opened up to 2 1/4" and a 2 1/4" exhaust system. Also removed the flapper. Hopefully that will make it breath a bit easier.