Need A Beffier Irs Differential
Race Director
Joined: Jan 2000
Posts: 13,011
Likes: 2,250
From: Corsicana, Tx
2020 C2 of the Year - Modified Winner
2020 Corvette of the Year (performance mods)
C2 of Year Winner (performance mods) 2019
2017 C2 of Year Finalist
Tom's Differentials. Pretty much the main folks messing with them.
Lots of 8 and 9 sec Vette's with them.
JIM
Lots of 8 and 9 sec Vette's with them.
JIM
Le Mans Master
Joined: Apr 2007
Posts: 7,353
Likes: 72
From: Graceland in a Not Correctly Restored Stingray
Mine isn't from Tom's, but I can attest that an Eaton based 12-bolt IRS diff conversion is the way to go. I'd upgrade your half-shafts at least to factory 3" pieces, and make sure to run solid Spicer U's, too.
Burning Brakes
Joined: Apr 2004
Posts: 847
Likes: 0
From: Des Allemands LA
Thanks,
ltlevil
Le Mans Master
Joined: Apr 2007
Posts: 7,353
Likes: 72
From: Graceland in a Not Correctly Restored Stingray
I could probably adjust that out and put it to use on certain courses, but the 4.11:1 proved too deep for the street and I'm not that into parking lot variety auto-Xing. The one currently in my SA was done by Henry's Machine Works using an Eaton posi and 3.55. I can't recall a name, as it's been about 20 years, but the guy who used to do Muldowney's diffs set it up. I've broken and upgraded other stuff since, but the diff has proved bullet proof. If I ever have to let go of my SA, this piece stays with me.
Burning Brakes
Joined: Apr 2004
Posts: 847
Likes: 0
From: Des Allemands LA
My first one was done by a local shop (long since gone) in Memphis using a tight Moroso posi. While it was fine in a straight line, the instability caused by ratcheting when trying to put power down in fast sweepers was undesirable, to say the least. I could probably adjust that out and put it to use on certain courses, but the 4.11:1 proved too deep for the street and I'm not that into parking lot variety auto-Xing.
The one currently in my SA was done by Henry's Machine Works using an Eaton posi and 3.55. I can't recall a name, as it's been about 20 years, but the guy who used to do Muldowney's diffs set it up. I've broken and upgraded other stuff since, but the diff has proved bullet proof. If I ever have to let go of my SA, this piece stays with me.
I could probably adjust that out and put it to use on certain courses, but the 4.11:1 proved too deep for the street and I'm not that into parking lot variety auto-Xing. The one currently in my SA was done by Henry's Machine Works using an Eaton posi and 3.55. I can't recall a name, as it's been about 20 years, but the guy who used to do Muldowney's diffs set it up. I've broken and upgraded other stuff since, but the diff has proved bullet proof. If I ever have to let go of my SA, this piece stays with me.
Can't blame you for wanting to keep it. Thanks for the info.
Steve
Team Owner
Joined: Nov 2004
Posts: 20,700
Likes: 25
From: Sorrento Italy
Just my personal experience.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
5 MOST and 5 LEAST Popular Corvette Model Years in History!
Joe Kucinski
2027 Corvette Buyer's Guide: Everything You Need to Know!
Joe Kucinski
10 Things C8 Corvette Owners Hate (But Won't Tell You)
Joe Kucinski
10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!
Brett Foote
