how would i figure out what rear end gears my car has? its an 84 z28...carbed 305 blah blah blah. is there some mathematical way to figure it out?

 

either 3:23 or 3:73 depends on if yours had the 305HO. the mathematical way is to pull the pan count the teeth on the pinion and ring and divide them together. Sick

 

Yea just what sick said. I wasn't going to reply since the question was answered but i just wanted to compliment sick on his really nice lookin car. How wide are those tires on there?

 

That would be add the ring and pinion and divide by two, right

 

thanks, it cleans up really well. they are advertised as 10's but actual rubber width is 12 almost 14 with the sidewall. they aren't wrinkle wall. they are actually nascar slicks. i got them for 25 bucks a piece with 90% tread. could'nt refuse that deal. once they are heated they bite really well and from what i've witnessed don't wear down as quick as wrinkle wall. since they are quite rigid it's not as much stress on my locked 7.62 carrier. after i get it tubbed and the rearend upgraded i'll invest in some drag slicks. Sick

 

Hey guys, the tooth count is stamped on the ring gear usually towards the end of a long string of numbers. A quick cheap way is to make a reference mark both rear wheels, referenced with the backing plate, then index the pinion. Turn both wheels equally one full turn while counting how many revolutions the pinion turns. This will give you an idea of what you got.