Gears for 72
Thread Starter
Intermediate
Joined: Mar 2003
Posts: 42
Likes: 1
From: Maryland
Gears for 72
3.55 or 3.73 which way to go? I'm getting ready to have my rear done in my 72 automatic. It's currently the way it came from the factory, I'm thinking maybe with 3.08's. Motor has some bolt on's but will be replaced later with something potent. I'm looking to build something "STRONG" for the street and still cruise the highways. Just looking for some thoughts from my fellow partners.
Team Owner
Joined: Dec 1999
Posts: 26,555
Likes: 257
From: Florida
2021 C2 of the Year Finalist - Modified
C2 of the Year Finalist - Modified 2020
C2 of Year Finalist (performance mods) 2019
St. Jude Donor '03 thru '26
I use to want to do the same thing, but changed my mind. The stock gears run great on the highway at low rpms (70mph @ 2400rpm). 
Melting Slicks
Joined: Nov 2001
Posts: 2,668
Likes: 43
From: Eastern US XX
Originally Posted by Akaswan
3.55 or 3.73 which way to go? I'm getting ready to have my rear done in my 72 automatic. It's currently the way it came from the factory, I'm thinking maybe with 3.08's. Motor has some bolt on's but will be replaced later with something potent. I'm looking to build something "STRONG" for the street and still cruise the highways. Just looking for some thoughts from my fellow partners.
Advanced
Joined: Feb 2004
Posts: 65
Likes: 0
From: marble falls texas
Hi akaswan
I think I would run with the 3.55 gears any higher and you won't like your highway rpm's. ! run a 406/475 hp. I have a 4.11 rear end and th350 it is lousy on the highway. It's like running your car in 2nd gear down the highway. But I run like a bat out of hell from red light to red light . Also mine is just a toy to play with. I was not worried about highway cruising.
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
3.55 with the auto. I have 3.70 gears and it was pretty tough on the highway. I went with the Tremec and am loving life again. The best of both worlds. Great low end with great cruising. It works out to be 2.51 overall in 5th gear. 3.70X.68=
Tech Contributor
Joined: Aug 1999
Posts: 15,175
Likes: 3,986
From: Connecticut, USA
I have 373's in a couple of 4 speed cars and the highway cruise is 3400@70 mph. With flowmaster 40's, the windows down, you get into "drone state of mind" quick! The only thing that willl snap you out of that mindless funk is the rapid movement of the gas gage as you maintain a steady 12 mpg 
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Race Director
Joined: Mar 2001
Posts: 11,322
Likes: 1
From: Living in the Hartland
Originally Posted by gtr1999
I have 373's in a couple of 4 speed cars and the highway cruise is 3400@70 mph. With flowmaster 40's, the windows down, you get into "drone state of mind" quick! The only thing that willl snap you out of that mindless funk is the rapid movement of the gas gage as you maintain a steady 12 mpg
I feel ya brother! Little better in a vert for noise but those 40's do sing a loud song at 3500 rpm's.
