gearing

[Sixty6]

I am going to be running a muncie m20 4 speed with 2:52 1st gear and 1:1 4th gear. I will be running this in a 1966 chevy pickup with 275/40-17 tires. I want to beable to cruise with it and still have good pull. This is coming out of a chevy nova that has a built 355 and 390 gears and it just ran out of gear to fast and you couldnt cruise with it, it was always tacked up. I was planning on going with 342 gears or 308's. Anyone have any suggestions.

[Dave Severson]

What is your tire diameter for the rear tires??? What RPM do you want to be at when cruising at 70 mph??? I have a program that will tell you what gear you need in the rear if you can supply me that information.

[lt1s10]

what interstate hwy. do ya'll cruise on? i used to cruise on broad st. and a 3:90 worked great.

[Sixty6]

The 275/40-17 tires that i want to run are about 26'' tall. I want to be able to cruise at 70 at about 2700 rpms. thanks

[Dave Severson]

Ideally, that would be a 2.98:1 gear ratio. Make your gear purchase from there.

[Sixty6]

could you tell me where i would be with the same set up but with 324:1 gears and 308:1 gears. in rpms. Thanks for the info

[Sixty6]

I meant 342:1

[Dave Severson]

Here ya go, with a 26" rear tire @ 2700RPM

with 3.42 gear=61mph
with 3.08 gear=67mph
with 2.73 gear=76mph

If you want more mph at less RPM, going to a taller tire would help, too

28" tire at 2700 RPM would be:

with a 3.42 gear=65mph
with a 3.08 gear=73mph
with a 2.73 gear=82mph

[Sixty6]

thanks alot

[chevydrivin]

Here is my home made version. Go to the miata link to get tire circumfrance.
Don't mess with the yellow cells. Its already set up for M20 (thats what i am running). Top cell enter tire size 25.7. Next put your rpm you want. then put you rear gear ratio. the bottom number is your speed for each gear. change it up all you want to see what it will be.

[Sixty6]

thanks

[OBmisfit]

can you set up a program like that for the TH350?

[lt1s10]

this will work also.

http://www.richmondgear.com/101032.html