Hey guys, just wondering what would work best with my application(see sig)presently I have the borg-warner 3:27 9-bolt posi-disc, or should I go to the 3:73? The tranny I have is the 700R4, Would I gain or lose performance if I choose the 3:73?
Any info would be great!

 

Ivan,

You are faced with a few questions that only you can answer.

Is your car meant for the strip only? If so, go for the 3.73s or even higher.

Most of us need our car to go to work, and visit ma and pa, and chase girls (or guys, as the case may be for all you gals), etc. Thus we shy away from such gears as 3.73s unless we have an overdrive tranny.

Honestly, most people are leery of going for 3.73s on the street and prefer 3.42s, 3.23s or even 2.73s. The latter are especially attractive for folks who travel the highways a lot.

All things being equal, 3.73s ought to get you an additional half second or so in the quarter mile, but cost you a fair penny more in gas.

 

Forget mpg, I went with 3:73s and this is my daily driver. I haven't noticed a decrease either. But one thing about your car. Stock TPIs stop breathing at 4500 rpms, which 3:42s would be the way to go, unless you have modded it.

 

yeah you should do away with the 3.27 posi rear disc and sell it to me and pick yourself a 3.73 rear up

 

Why do away with the entire rear? Just install some 3.73's (or even 4.10's) in current rear.

I run 3.73's on the street and love it (26 inch tire and no OD) I use to have 3.27's and have been very happy since I switched.

Miles

 

Because I think he just wants to buy the disc rear.

 

I would look at the engine rpm, you want to run at. I'm running 373s in my GTA, but turn the engine 6200 rpm. I also have a 77 T/A running a 400 Pontiac. Longer stroke, more torque. It runs real good with a 323 gear. Will the car perform better with the 373? Maybe, maybe not. Longer stroke engines tend to like taller gears. Just my 02 though.