Rear End Question
Thread Starter
Le Mans Master
Joined: Mar 2006
Posts: 5,262
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From: E. Amherst NY
Rear End Question
Hi -- I generally hang out in the C4 section, but some shopping around has me asking this. I'm looking to potentially buy a drag car, and an early C3 seems like it's a strong candidate.
My question is how much power will a stock '68-'75 differential put up with at the drag strip? Anything that anyone has pertaining to this would be much appreciated.
Chris
My question is how much power will a stock '68-'75 differential put up with at the drag strip? Anything that anyone has pertaining to this would be much appreciated.
Chris
Team Owner
Joined: Jul 2001
Posts: 182,997
Likes: 88
From: Lakeland, FL
Cruise-In IV-V-VI-VII-VIII Veteran
St. Jude Donor '03, '06, '17
Hi -- I generally hang out in the C4 section, but some shopping around has me asking this. I'm looking to potentially buy a drag car, and an early C3 seems like it's a strong candidate.
My question is how much power will a stock '68-'75 differential put up with at the drag strip? Anything that anyone has pertaining to this would be much appreciated.
Chris
My question is how much power will a stock '68-'75 differential put up with at the drag strip? Anything that anyone has pertaining to this would be much appreciated.
Chris
About 400 HP with slicks
Up to 600 HP with street tires (not Drag Radials)
2) automatic cars without transbrake:
About 550 - 600 HP with slicks
About the same with street tires..
with transbrake: 400 HP with slicks and 600 HP with street tires (as they will spin off the line with the transbrake)
As soon as you hook with transbrake or a hard stick shift launch, your rear won't live too long with 400+ HP.
Lucklily, there is a IRS setup that will hold up to over 1000 HP which is Tom's 12-bolt IRS which is almost bulletproof..
Thread Starter
Le Mans Master
Joined: Mar 2006
Posts: 5,262
Likes: 0
From: E. Amherst NY
Thanks Olivier! 
Car would definitely be an automatic because it would be a dedicated strip car. Definitely wouldn't run a transbrake before I went to a Tom's setup. Part of the reason I was hesitating to seriously consider a C3 was I didn't want to shell out the money right away for a Tom's setup. 550hp sounds like it's about where I'd want to be for a while.
I actually didn't realize the stock IRS would put up with that much power. Should've considered what the stock Big Blocks were putting out torque wise.
Car would definitely be an automatic because it would be a dedicated strip car. Definitely wouldn't run a transbrake before I went to a Tom's setup. Part of the reason I was hesitating to seriously consider a C3 was I didn't want to shell out the money right away for a Tom's setup. 550hp sounds like it's about where I'd want to be for a while.I actually didn't realize the stock IRS would put up with that much power. Should've considered what the stock Big Blocks were putting out torque wise.
Team Owner
Joined: Jul 2001
Posts: 182,997
Likes: 88
From: Lakeland, FL
Cruise-In IV-V-VI-VII-VIII Veteran
St. Jude Donor '03, '06, '17
Thanks Olivier! Car would definitely be an automatic because it would be a dedicated strip car. Definitely wouldn't run a transbrake before I went to a Tom's setup. Part of the reason I was hesitating to seriously consider a C3 was I didn't want to shell out the money right away for a Tom's setup. 550hp sounds like it's about where I'd want to be for a while.
I actually didn't realize the stock IRS would put up with that much power. Should've considered what the stock Big Blocks were putting out torque wise.
Car would definitely be an automatic because it would be a dedicated strip car. Definitely wouldn't run a transbrake before I went to a Tom's setup. Part of the reason I was hesitating to seriously consider a C3 was I didn't want to shell out the money right away for a Tom's setup. 550hp sounds like it's about where I'd want to be for a while.I actually didn't realize the stock IRS would put up with that much power. Should've considered what the stock Big Blocks were putting out torque wise.
Tech Contributor
Joined: Aug 1999
Posts: 15,175
Likes: 3,987
From: Connecticut, USA
Good point- depending on the year you'll have 10-18 or 10-17's. The 17's are much better but the stock rebuilds are sloppy. If you're going to push it hard you need heat treated 17's, solid clutches, polished case, HD cross shaft, and ARP RG bolts. Add a steel cap and solid sleeve.
Team Owner
Joined: Jul 2001
Posts: 182,997
Likes: 88
From: Lakeland, FL
Cruise-In IV-V-VI-VII-VIII Veteran
St. Jude Donor '03, '06, '17
Good point- depending on the year you'll have 10-18 or 10-17's. The 17's are much better but the stock rebuilds are sloppy. If you're going to push it hard you need heat treated 17's, solid clutches, polished case, HD cross shaft, and ARP RG bolts. Add a steel cap and solid sleeve.
Melting Slicks
Joined: Feb 2004
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From: State of Confusion!!!
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