I have 3.23 gears in my car right now, and I'm thinking about changing them out. I was thinking either 3.73 or 4.11. Does anybody have a stock (or pretty much stock) car with either of these gears, and can you tell me what rpm's you run and what kinda gas milage you get?

 

for a automatic trans, i wouldnt go any higher than 3:73's, and automatic with 4:10's will have terrible gas mileage and will also suck driving on the highway

 

I know pretty much everybody says only use 4.11 on the t56, but I was just curious if anybody had any numbers on rpm's, and gas mileage...I've been planning on putting in the 3.73's, but started to wonder. Also, how big of a difference is it between 3.23's, and 3.73's? I mean, how much quicker does it actually feel?

 

i think you'll get better gains out of a stall convertor, instead of gears at this point..but for what u asked about, check this "calculators" out
https://www.camaroz28.com/services/calcs/
ANy mods other than the flowmaster?
As long as you got the 3:23's which is a decent gear for the auto, i would get a stall convertor.