Perfect gears for TH350??
Perfect gears for TH350?? What i want is for the car to turn decent RPM's @ 70mph (3500 or less probably) and bury the speedo at will. but still not be a dawg on bottom end or when runnin through the gears. I know for it to do all that extremely well would be asking alot, but im just looking for a good compromise.
The car is a 98 T/A with cam, built TH350 (3200-3600 3.75str stall), nitrous, 28" rear tires, and bolt-on's.
Gears to choose from:
2.73 (pretty sure it will be a turd)
3.08
3.23
3.42 (perfect street strip?)
3.73
It's had 4.10's in it with a 25" tire and it topped out around 125mph...not cool at all. so i know those are too low.
Also, would it help me to put that 2.75 first gear in it for a better launch with higher gears? Or should I leave 1st the way it is since i will be on Drag Radials most of the time?
I know its lots of questions, but i wanna get it right....thanks alot for any help/info!!!
The car is a 98 T/A with cam, built TH350 (3200-3600 3.75str stall), nitrous, 28" rear tires, and bolt-on's.
Gears to choose from:
2.73 (pretty sure it will be a turd)
3.08
3.23
3.42 (perfect street strip?)
3.73
It's had 4.10's in it with a 25" tire and it topped out around 125mph...not cool at all. so i know those are too low.
Also, would it help me to put that 2.75 first gear in it for a better launch with higher gears? Or should I leave 1st the way it is since i will be on Drag Radials most of the time?
I know its lots of questions, but i wanna get it right....thanks alot for any help/info!!!
TECH Enthusiast
Joined: Feb 2004
Posts: 743
Likes: 0
From: Foley, Alabama-southern Alabama
The 3.42"s should work with that stall,I wouldn"t change the tranny gears.I don"t know exactly what rpm you will turn at 70 mph.I have 3.42 gears in a 1981 Camaro with a 4 speed and 28 inch tires and it turns about 2600 at 60 mph at 70 mph it would be 3015 rpm. With 26 inch tires it would be 2782 at 60 and 3226 at 70,plus the added rpm from the convertor slippage.Should be pretty close,to what you want
TECH Enthusiast
Joined: Feb 2004
Posts: 743
Likes: 0
From: Foley, Alabama-southern Alabama
I had a 79 Camaro with a th350 and 3.42 gears and the stock tires it turned 4400 at 100 mph,3000 at 60(stock convertor),it would run about 145mph (at least thats as fast as I would go) 
A top speed caculator says that with 28" tires and a 6600 limiter it will.....
3.42's 70MPH @ 2900 (plus convertor slippage i figure)
Top speed 160MPH @ 6600
3.23's 70MPH @ 2750 (plus sluppage again)
Top speed 169MPH @ 6600
According to this, i figure i will turn the same RPM @ 70 with either gear beacuse of the convertor slippage correct?? So with that said, I would only lose 9mph top speed and probably gain alot of takeoff and midrange with the 3.42's right?? So far im figuring that will be the gear of choice, I just want some opinions. Thanks for the info guys!!
3.42's 70MPH @ 2900 (plus convertor slippage i figure)
Top speed 160MPH @ 6600
3.23's 70MPH @ 2750 (plus sluppage again)
Top speed 169MPH @ 6600
According to this, i figure i will turn the same RPM @ 70 with either gear beacuse of the convertor slippage correct?? So with that said, I would only lose 9mph top speed and probably gain alot of takeoff and midrange with the 3.42's right?? So far im figuring that will be the gear of choice, I just want some opinions. Thanks for the info guys!!
