okay i'm just wondering whether you can figure out your rear end gear ratio by speed and transmission gear ratio. On the highway i'm going 70 and its spinning about 2500 rpm. i have a th400 trans but third gear is 1:1. does anyone do a calculation and tell me what gears i have or give me an equation to figure it out myself any help would be appriciated. oh by the way stock tires and rims.

 

Don't bother. Your tach is not accurate enough.

Take off the cover and look, if it really matters to you. All else is monkey-spank and speculation. Besides, if you really care about this car, you need to change the fluid anyway; while you're catching up on the long-overdue maintenance, make a point of looking at the gears.

Same for the next question you're probably about to ask: how can you tell if you have posi.

 

umm no i have an autometer aftermarket tach but thanks for the input any ways

 

https://www.thirdgen.org/newdesign/t...ulations.shtml