3.42 gears vs 3.08 gears
#1
3.42 gears vs 3.08 gears
I have a convertible 1971 oldsmobile cutlass supreme. The engine is a 350 and the car has a 3 speed hurst shifter. I'm putting a 8.5 10 bolt posi rear end with mosier axles in the car. the tire size is 235 60/14. I have the choice of 3.08 gears or 3.42 gears. Based on the information given (I hope it's enough information) which gears would be a better setup. I think my engine pushes out 360 to 380 hp. I want to be fast off the line but I don't want to be screaming doing 75 on the freeway. Thanks in advance for your help!
#3
http://www.angelfire.com/fl/procrastination/rear.html
This program will show you your engine rpm once you plug-in the other information.
It helped me when I was pondering like circumstances.
This program will show you your engine rpm once you plug-in the other information.
It helped me when I was pondering like circumstances.
#9
Fyi
[QUOTE=hilbily;738472]I've got 3.08 in mine and I'm going with a lower gear soon, just haven't decided, was thinking right around a 3.50. Kinda depends on what's available for a 12 bolt.[/QUOTE
Chevy 12 bolt has 3.31s & 3.55s available. Olds 12 bolt uses 3.42s.
Chevy 12 bolt has 3.31s & 3.55s available. Olds 12 bolt uses 3.42s.
#10
I have a convertible 1971 oldsmobile cutlass supreme. The engine is a 350 and the car has a 3 speed hurst shifter. I'm putting a 8.5 10 bolt posi rear end with mosier axles in the car. the tire size is 235 60/14. I have the choice of 3.08 gears or 3.42 gears. Based on the information given (I hope it's enough information) which gears would be a better setup. I think my engine pushes out 360 to 380 hp. I want to be fast off the line but I don't want to be screaming doing 75 on the freeway. Thanks in advance for your help!
If you engine actually pushes out 360-380, you've got more than 300 ponies at the wheels. The torque number has to be right there too. I don't think you need the 3.42. Might have trouble keeping traction.
I've got 3.23's in the rear, and at 80 she's turning loud. But mines a stock build, your 350 is nowhere near stock.
How often are you on the highway? Once a week in the good weather, once a month? 2x a season? That's the major factor. If you rarely travel on the highway, or do so very infrequently, I wouldn't worry, it'd get the 3.42
#13
I've got a 3.23 posi in my 73 442 and do a fair amount of highway driving. It's turning close to 3,000 rpm at 75 mph which is enough engine noise for me on extended trips.
I agree with the others if you do alot of highway driving I would not put 3.42's in your car. I'd stick with a 3.23 or a 3.08 gear ratio. If your goal is more performance and most of your driving is city streets and rarely highway, then go with the 3.42 gears.
I agree with the others if you do alot of highway driving I would not put 3.42's in your car. I'd stick with a 3.23 or a 3.08 gear ratio. If your goal is more performance and most of your driving is city streets and rarely highway, then go with the 3.42 gears.
Thread
Thread Starter
Forum
Replies
Last Post
monzaz
Drivetrain/Differentials
6
August 7th, 2014 11:12 AM
shaks 442 clone
Drivetrain/Differentials
8
May 14th, 2008 04:01 PM