I have a 92 Pontiac Firebird with a 305 tbi and a 700r4 transmission but I don't know what the gears are. Does anyone know what those came with and if it was a 26 spline or 28 spline? I have a new Richmond 3.73 gears for a 7.5in 10 bolt Chevy rear end and a new posi differential for a 28 spline and I just want to make sure they are going to work before I start taking things apart and I'm out of a car for a couple of days.

 

I'm not tryn to be a azz but i'm going to say, that if you can't figure out what gears you have in your car now, maaaybe you shouldn't be swaping gears in your own car.

 

Well maybe you shouldn't worry about that. I didn't say anything about installing. I just want to know the gears so if you have nothing good to say just keep it to yourself

 

 

https://www.thirdgen.org/forums/tran...-10-bolts.html
Everything you need to know is right here.

 

Heres a link to check out = https://www.thirdgen.org/1992-pontiac-firebird

 

Thank you. I got the gears and differential changed out. Yes TTOP350 I did it myself and it runs great.

 

Thats good to hear, I'll sleep better knowing that.
How did you correct the speedometer?

 

305 TBI auto more than likely has 2.73

 

I pulled off the extension housing on the transmission and pulled the old speedometer gears out and my brother did a calculation to figure out which speedometer gears I needed for my rims and tires and the new gears and just got one from his work and installed it. Yes they were the 2.73

 

If you went from a open 2.73 differential to a 3.73 posi. than you must be happy as far as the difference goes. I went from a 2.73 to a 3.42 with a Eaton posi. and L.P.W. Support cover and it was like night and day. Congratulations. One of the other things I did was put a Corvette servo into the 700r4 and it really tightened up the shifts.

http://www.sethirdgen.org/servo.htm

 

I love the difference. The gas milage went down a ton but hey I don't drive a muscle car for the fuel economy