Orr89RocZ

iTrader: (20)

i got a posi for my 9 bolt with 3.27 gears. they go in after winter. LOL i cant wait.

i got 2.77 in now and with my 2800 stall and adjustable shocks, i got a 14.02 at abit over 96mph. still more in it so i figure 13.9's with it now as is.

my car is stock L98 TPI with full exhaust. i need LCA's and brackets as well as a new cat converter. its mostly daily driven on good days. but next year i will try to keep it under 5000miles to avoid emissions testing.

anyway, will 3.70's show much improvement over 3.27's? i think it will make me launch quicker and run faster 1/8, but will hurt my 1/4 time. i hear both good and bad about those gears with auto TPI's. what do you think? i do plan on either stealth raming it (if get emissions exempt) or super ram some day. maybe BBK's intake if its nice and has higher rpm range.

Blu91Z28

Unless you're planning the intake swap anytime soon, I'd stay with the 3.27's.

leeperryracing

why not some 4.88's?...just kidding LOL!! if you can get your tpi to make power to or past 5k then 3.70's would transform that car.

TPI-Formula350-

i swapped out my 3:27s for 3:73s but I also swapped out my stock TPI for a Super Ram and hih-flo base around the same time. I wouldnt change out your gears unless your going to have your car breathing well on the intake side as well as your exaust. good luck with it

slim84maro

the bigger gears will suck on the highway.

brutalform

TPI-Formula350- Were you at a GMHightehPerformance shoot at Englishtown in Sept or Oct. of 1996?...Tom

Floor guy

3.27 is the gear "I" would use.

92RSZ

iTrader: (6)

3.73s will most likely hurt 1/4 mile times. with that gear and tpi, the motor will start to fall on its face at around 1000 ft. 3.27 - 3.42 will keep the motor in its sweet spot through the traps. I went 13.89 with 3.42 gears and a crappy 2000 stall when i still had the stock tpi and cam. do 3.73s for sure if youre changing the intake.

TPI-Formula350-

no, but i'll be going to Etownfrom now on because they just closed the last 1/4 mile on Long Island...

brutalform

I know this is a bit off topic, but your car, and, where you are from makes me think of a guy I met at a GM hightech magazine shoot. Nice Formula. Sorry for being off topic....Tom

Orr89RocZ

iTrader: (20)

thanks, i do plan on doing a super ram or stealth ram some time in the next year or so as well as a new motor. LOL, nothing too great, just something to get me by for the time being. LOL

its a daily driver in the summer time, but i want to try and keep it under 5000 miles next year to avoid emmissions testing, so i can go stealth ram LOL

i want 3.45's but feel that 3.70's and 2800 stall (more like 3000) will be too much on the street for low rpm launches.

1989GTATransAm

iTrader: (3)

I have 3.70's on my car and I get no traction on street tires. It just spins. If I had to do it over again I would have went with the 3.45's. or just stayed with the 3.27's.

Like was said above if you are going to something like a Minram, Holley Stealthram or Accel Superam then maybe the 3.70's. You need something to kill off some of the low end torque of the TPI for 3.70's and trade it for upper rpm horsepower. Allen

blacksheep-1

FYI the stock gear ratio in an 83 L69 was 3.73
I was running 4.11's but the 3.73's made a better autocross/street gear. But hey, I used to drive 60miles a day with a set of 5.13's.