Gear ratio selection ?

[Warputer]

The old 12 bolt has a 2.56 or 2.59 right now & is really weak off the line. My buddy that helps me with most of my vehicle issues has recommeneded a 3.73 ratio, especially since the car is mainly just used to run around town locally with no time on the Interstate. My main question is will a 4.10 be a huge difference in driveabilty (rpm's) versus the 3.73 .......and what are you guys running/recommend?

Thanks for any input you might have.

[shadowgray396]

If you 69 has a olds rear under it I would get rid of it. The olds rear ends are not really a 12 bolt, but a weak 10 bolt with a 12 bolt cover. Parts for them are expensive. My first 70 chevelle came with an Olds rearend under it. I would look for a 12 bolt. You can sell the Olds rearend to someone who is restoring a 442 or and Olds car. Check the numbers and date code and see what it came out of. I personally would run a 3.73 over a 4.10 especially if you plan to drive it on the interstate.


Olds rearend
http://s777.photobucket.com/albums/y...=Olds-Rear.jpg

[Hank70SS]

Chris, I don't remember if you mentioned it but what engine and trans?

I have a 3.73 behind a 454 and M20 trans. It's just for cruising, no racing but it does get on the freeway sometimes. I would really prefer a 3.42, of course the 454 has a lot of low end torque so I don't need a high gear ratio to get the thing moving.

[Warputer]

Originally Posted by Hank70SS

Chris, I don't remember if you mentioned it but what engine and trans?

I have a 3.73 behind a 454 and M20 trans. It's just for cruising, no racing but it does get on the freeway sometimes. I would really prefer a 3.42, of course the 454 has a lot of low end torque so I don't need a high gear ratio to get the thing moving.

A 350ci & 2 speed Powerglide.......mine is just for cruising also. Probably never see an Interstate, so higher rpms don't really matter to me.

[Highway Star]

You should, in that case, buy a set of 4.10 or 4.11 gears and never look back.