Not sure if this is the right place to post this question but here goes. I have a '80 camino, with 305 and th350. the th350 is bone stock to my knowledge. My top end is 115 @5100 rpm. what does that tell me about my rear gearing? If its stock it should be 2.73 i think. Thanks for any help here.

 

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

 

Whats the GU code?

 

sorry, what is a gu code?

 

its an RPO code, usualy located in the door jamb.

http://www.c2e.info/rpocodes/gmrpocodesGthroughM.html

that link is for the G's

 

My car has had a paintjob so i cant tell if there is anything in the door jam, and theres nothing on the cowl tag.

 

jack the car up, spin the rear tire around one full 360 degree revolution (make sure the other wheel revolves equaly with the tire you are spinning) count how many times the drive shaft rotates for every one rotation of the tire.