My rear axle seal is leaking, and I was wondering about putting in a posi rear end, and the best gear ratio to go with. It is a 92 RS with a 305 tbi, and 770R4 tranny. I primarily use the car as a daily driver, but I do want to hop the car up to the next level. Thanks.

 

3:42 ought to be a good choice, what do you have now?

 

3.42 or 3.73. You would want a little bit higher stall converter with the 3.73s, and a bigger cam, better intake, & better heads also wouldn't hurt. All assuming that the exhaust has already been opened up.

I'd go with the 3.73s because they offer you more flexibility down the road as you make other improvements.

 

Sorry my typing was off yesterday, it is a 700R4 Transmission, I will have to crawl under the car tomorrow to find out which ratio I have. Thanks

 

Chances are you probably have the 2.73 ratio. That's the ratio I've seen in pretty much every 305 TBI car with the 700r4.