Not necessarily true. I went from 14.7's to 14.0's after just the gear change to 3:73.

 

Ya, if you came from a 2.73 gear. Thats a worthwhile change.

 

BTW, I'd stretch for a 12 bolt or 9" instead.

 

I dont know a thing about rears but what would you expect this Jasper 3.42 rear have as for bolts etc?

 

97 SS M6. Went from a 3:42 to a 3:73.

 

Dunno, its been a long time since I kept track..

Its a tradeoff of headaches IMO.

A direct 10 bolt replacement, new or junkyard, you'll never have to worry about special parts, and shouldn't worry about sutff fitting and what not. But, you still have that weak 10 bolt in the back.

An aftermarket 12 bolt or 9 inch... Costs a bit more.. since its aftermarket, you have to keep an eye on production tolerances(measure and check everything).. Maybe some special parts or tricks (like brake mounts, tq arm mount, abs setup, or not, some are pratically direct bolt in) The rest of the stuff is common enough that any half decent shot can work on them though. But you havea much stronger rear.


That said and done, Iwent with 10 bolt repacement. but if could go back in time, i would have waited a bit longer and spent some more money to get a 12 bolt setup (to keep 3 channel abs in the rear).. OH well, so far the 10 bolt is holding up agian.

 

Yea I was just looking at my new rear on the lift today and its a 10 bolt,, even mentioned a 12 bolt to him and he said these things are more then tough enough and no reason to go with a 12 bolt. So I am happy, plus Im having him look into what its gonna run for headers, Flowmasters and an electric cutout.... cause this guy has one sweet sounding F**d C***a with that setup and I was creaming my jeans at the sound and then he flipped the switch and I was sold.

 

So you mean to tell me in that with that small of a change, you dropped a consistant 7 tenths in the 1/4?

I find that beyond hard to beleive. Ive seen auto cars go from 3.42 to a 4.10 and not pick up that much.

 

3.73s for sure man..

 

Yes that's what I'm saying. There's is no question that it is unusual, and I would never tell someone that they "would " get this much improvement.
Track condition were the same and so was the weather, DA. And this was an average of .6+ difference over 5 runs each. Two things that may have done it were moving the shift points so I was pulling harder though the traps and the fact that the car weighs 3800lbs.

 

@ 3.42>3.73 dropping .7 in the quarter mile.

 

I figured this was coming!
Aaaahhhh didn't you get .7 off then you did your swap?????
Maybe it's the DRIVER!!!

 

Well if you were short shifting yourself before, then ya, I might beleive it, but that is not a .6 gain on gears alone.

 

I mean not talking highway mileage which wont get changed by much what do you guys think are better for performance 4.10s or 3.73s? in the 1/4.

 

Depends on your powerband. I think you might be surprised how it effects your mileage, unless you have an M6, then you can keep pretty low rpm's at cruising speeds. Usually a 3.73 is sufficient either way IMO.