WTB: Wanted: 3.91 or 4.11
Thread Starter
Instructor
Joined: Apr 2025
Posts: 163
Likes: 46
Wanted: 3.91 or 4.11
Hey guys, First, thanks for all the good info on my gear upgrade project. But, I think it’s going south. I spoken To Jim at V Tech and he can’t seem to locate a quality 4.11 or even a 3.91. It’s not going to be worth swapping up to a 3.70 from the 3.36. Any thoughts on finding a GOOD used 4.11 / 3.91 ? But, that’s going to add considerably to the entire cost of doing this.
Car currently has the OE 1971 base 350/270, M20 4 speed and the 3.36 gear. ( Entire driveline was rebuilt to OE specs )
Any thoughts, suggestions… He wont put in any Chinese junk gear and the info quality one he’s got available is a 3.70. But, all the posts I’ve read have convinced me that I probably wont even feel the difference going to the 3.70.
Thanks guys, Steve
Car currently has the OE 1971 base 350/270, M20 4 speed and the 3.36 gear. ( Entire driveline was rebuilt to OE specs )
Any thoughts, suggestions… He wont put in any Chinese junk gear and the info quality one he’s got available is a 3.70. But, all the posts I’ve read have convinced me that I probably wont even feel the difference going to the 3.70.
Thanks guys, Steve
Instructor
Joined: Jan 2023
Posts: 163
Likes: 12
Hey guys, First, thanks for all the good info on my gear upgrade project. But, I think it’s going south. I spoken To Jim at V Tech and he can’t seem to locate a quality 4.11 or even a 3.91. It’s not going to be worth swapping up to a 3.70 from the 3.36. Any thoughts on finding a GOOD used 4.11 / 3.91 ? But, that’s going to add considerably to the entire cost of doing this.
Car currently has the OE 1971 base 350/270, M20 4 speed and the 3.36 gear. ( Entire driveline was rebuilt to OE specs )
Any thoughts, suggestions… He wont put in any Chinese junk gear and the info quality one he’s got available is a 3.70. But, all the posts I’ve read have convinced me that I probably wont even feel the difference going to the 3.70.
Thanks guys, Steve
Car currently has the OE 1971 base 350/270, M20 4 speed and the 3.36 gear. ( Entire driveline was rebuilt to OE specs )
Any thoughts, suggestions… He wont put in any Chinese junk gear and the info quality one he’s got available is a 3.70. But, all the posts I’ve read have convinced me that I probably wont even feel the difference going to the 3.70.
Thanks guys, Steve
Burning Brakes
Joined: Oct 2004
Posts: 801
Likes: 17
From: Middletown Delaware
I have a 4.11 rear out of a 66 vette that i replaced with 3.55 rear. i have it ilisted on facebook and craiglist. https://delaware.craigslist.org/pts/d/middletown-corvette-411-rear-diff/7905391901.html
Last edited by Dave Witman; Jan 30, 2026 at 06:45 PM.
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