Pontiac GTO Forum banner

1965 Factory Rear Axle Replaced

8K views 8 replies 4 participants last post by  Margey 
#1 ·
Hey Guys,

Anybody know of a way to find out what the original factory rear axle would have been? Currently restoring my 1965 GTO which was purchased brand new by my Grandpa. Everything is original except for the rear axle and differential.
Originally was a Safe-t-track but was replaced with a standard rear end after he cracked the casting. Not even sure what the original ratio was. I know there was about seven options. Currently looking at an original 10 bolt Safe-t-track with a 3.08 ratio.
 
#8 ·
3.08 did come with M-20 equipped 4 speed cars. It was the highest gear you could get with a stickshift. Not a bad choice with $4 gas these days, either, if you want to drive the car. 3.23 is my all around personal favorite ratio for a 4 speed car. Plenty of power everywhere, and still fine on the freeway. I used to run 3.55's way back when, when the speed limit was 55...but now, I run 3.36's in my own '65. 3.55's are good for about a 60mph cruising speed, 3.36's will let you cruise 70 at around 3000 rpm. 3.08s, even better. Good luck with your project!!!
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top