Which rear end ratio do I have?
Thread Starter
Burning Brakes
Joined: Oct 1999
Posts: 1,041
Likes: 1
Which rear end ratio do I have?
The question of the day is "how can I easily tell what rear-end ratio I have in my '69 Vette."
It was originally a 427/435hp car with either a M21 or M22, but now has a 454ci mated to a TH350...but the rear-end appears to have never been changed or replaced. It's a posi-rear.
Anyone have any ideas for how to tell which rear-end based upon RPMs at certain speeds etc...or if 427/435s had a specific ratio?
Thanks!
Sam
It was originally a 427/435hp car with either a M21 or M22, but now has a 454ci mated to a TH350...but the rear-end appears to have never been changed or replaced. It's a posi-rear.
Anyone have any ideas for how to tell which rear-end based upon RPMs at certain speeds etc...or if 427/435s had a specific ratio?
Thanks!
Sam
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
Rotate the tire exactly one revolution. Count the number of times the pinion goes around in 1 tire revolution. If it goes around 3 1/4 times a 3.36. 3 1/2 turns 3.55, 3 3/4 turns a 3.70 and so on. You could get the numbers but seeing that someone has changed things on your car I would not trust the numbers.
