hey i have an ls1 with headers and fastchips i want a 3.73 gear. will i lose alot of gas milage and what will i lose on top end. does anybody know what the rpms are cruising on the highway at about 80 mph. or what gear should i go with thanks

 

I have 3.73's installed in my 2001 A4, and do ALOT of freeway driving, I have lost 20 miles per tank of gas, however the car is far more responsive. Try this sight and plug in the numbers:


http://www.f-body.org/gears/

Get the gears, you will love them.

SteveC

 

On my last auto, I had 3.73's.. They are fun gears no doubt. You do lose a little gas mileage but the fun factor goes up a bit.

I used to run at over 150 with 3.73 so I dont think you will have any issues with the top end.

 

Yea...I have a 4.10 on my Camaro 4speed auto. I can run up to about 105mph maybe more on 3rd gear. I would not recommend it for a stock engine though. It`s just not strong enought to keep good accelerating at high speeds with such a big gear and I am not even talking about 120 mph+...around 80 - 90 car whines a lot but is not pullling as hard. See I am getting nice set of heads and cam so that would change. Tahts the only reason I got those gears...cuz I knew that I will add some nice HP. But 1st and second gear with 4.10 is INSANE ! I remember when I first launched my car with all bolt ons and taht gear. I burned my drag radials like crazy..all the way thru 1st and second gear AUTO... thats pretty nutz.
So if u wanna keep your engine pretty much stock for now get 3.73. If You wanna put nice heads and cam...get 4.10 and nice set of tires and You`ll launch like never b4.
Take care.

 

80 mph = 3000 rpms
70 mph = 2600 rpms

 

i think i will get the 3.73s thanks everybody

 

You'll lose about 2 mpg over the 2.73s but more than doyble your fun!