rear end rebuild
Thread Starter
Burning Brakes
Joined: May 2008
Posts: 948
Likes: 1
From: pensacola fl
rear end rebuild
I'm going to have some surgery after the 1st of the year and was thinking about having the rear end of 76 with 4 speed upgraded. The engine was rebuilt locally a couple of years ago and upgraded with heads, cam , manifold, exhaust, etc. but still looking for more off line zip. I do some highway driving but overall it is a bit limited.
I was wondering what gear ratio would make a difference and still allow me to use it as a daily driver on nice Florida days?
I was wondering what gear ratio would make a difference and still allow me to use it as a daily driver on nice Florida days?
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
The best upgrade you can do is put in a 5 speed with an overdrive. This way you have more gear in the lower gears and a nice highway cruise gear. Best of both worlds. If you put in a 3.55 or a 3.70 for better acceleration you will lose your cruise rpm. I run a 3.70 gear in mine with a Tremec 5 speed and cruise at 70 mph at about 2200 rpm. Go onto Keislers website and find their calculator and play with the rear end numbers and see what your rpms will be.
Burning Brakes
Joined: Sep 2008
Posts: 805
Likes: 5
From: Naperville Illinois
I have a '68 small block with a TH400. I swapped out my original 3.08 for a 3.73 and love it. I don't spend a lot of time on the highway, but 3200 to 3400 rpm will get me as fast as I ever need (even on the expressways around Chicago) and doesn't bother me or seem to bother the car. Fuel economy is a different matter of course...
I recommend the US Gears from Tom's Differentials. I set them up and installed them myself, never having done it before, and they are quiet.
I recommend the US Gears from Tom's Differentials. I set them up and installed them myself, never having done it before, and they are quiet.
