the car
1968 Chevelle
healthy 454
4 spd
411 rear gears
and 255/50-17 rear tires

i want to go with a more highway friendly gears but i don't want to loose too much low end power.
thanks.

this post is for my cuz.
i suggested for him to go with 323s
but what do you guys think.

I had a set of 3:31's in my car before going up to 3:73. I quite like the 3:31's....they were a nice all round gear.

3.55s and 275/60/15 tires, 28" tall. Ran that for years with an M20.

Do you have an m20 or m21 or m22? The M20 has a 2.52 1st gear; the M22 has 2.20.

It's a consideration, as well as tire diameter.

Any more suggestions??

3:31's, hands down. I love Mine, and I've used just about every ratio.

Do you know what series his carrier has I assume itīs a 12 bolt rear? If itīs a 4 series carrier it wont accept any numerical lower than 3.73.

Marcus

the car
1968 Chevelle
healthy 454
4 spd
411 rear gears
and 255/50-17 rear tires

i want to go with a more highway friendly gears but i don't want to loose too much low end power.
thanks.

this post is for my cuz.
i suggested for him to go with 323s
but what do you guys think.

Well, since you have those small diameter tires you need to make a big move on the rear. If gas economy is the issue I would drop into the 2s but that will kill the low end unless the motor has been built with this in mind.

I had a friend of mine who did a rat motor in a 70 camaro, 4 speed and 9 inch rear, car got over 30 mpg on the CA freeways, had a 2.56 gear I think.

The cheapest thing you could do is put a tire on the back, like a 285X60X15 then back the gear off to say a 3.55, that will help a bunch.

i got a 3.55 with 275/60/15s...i would rather do a 3.31 or so for the amount i drive it but its not that bad. 3.55-3.23 would be roughly where he prob wants but the deciding factor would be where he drives it the most and where the engine operates the best and such. As mentioned...tire size will help overall too when making this decision

Up Date
The gear issue is not resolved yet but the plan has changed a little bit, he is now going with a 5 speed Trans to see if he likes the feel of it. Then he will go back to drawing board.

New combo coming soon
1-525 HP at the motor
2-5 speed Trans
3-and the same 255/50-17 rear tires not changing tires any time soon.

What do you guys think about the new planned combo?

Any more suggestions??

http://www.gearvendors.com/faq.html

Up Date
The gear issue is not resolved yet but the plan has changed a little bit, he is now going with a 5 speed Trans to see if he likes the feel of it. Then he will go back to drawing board.

New combo coming soon
1-525 HP at the motor
2-5 speed Trans
3-and the same 255/50-17 rear tires not changing tires any time soon.

What do you guys think about the new planned combo?
1-enough power
2-what is OD ratio?
3-still need a taller tire
If 1st gear is tall enough you could still go to a higher gear in the rear, (like 3.73) and not lose anything off the line.

Ttt.......

Like is said before this is my cousin’s car he just started looking at gears again and is most likely going with the 3.42s and a 28 inch tire. He is still going to build the motor and his target is still 525 HP. I also think that he can run a numerically lower gear like 3.23-3.36s but his big fear is loosing too much in off the line.

Am I wrong to think that he wouldn't have a problem off the line with a combo that looks like this 525 HP, 4 speed (M20), 27 inch tire and 3.23 OR 3.36s?

Is this for a 12 bolt? :confused:
If so, I've got a nice set of 12 bolt 3.31 GM gears available if interested...

He shouldn't have a problem I wouldn't think. I drive a 2.20/3.31 set up. It's not a rocket off the line, but if you've got enough engine once it gets rolling it should be a good running car.

A wide ratio Muncie, and a gear somewhere in that area should be good for daily driving. 3.36's and an M20 would net a 8.47 first gear. That should be pretty good gearing for a car that sees a lot of town miles. I don't know if that is his intent or not, but for me it works quite nicely. There is temporarily a Super T with a 2.64 first gear in the '70. That gives an overall first gear of 8.74. To be honest I wouldn't want much more gear than that for a car that is mostly driven on the street. But each person has their own preferences.

A couple of thoughts....If he is actually pulling the power he'd like, he's going to need to be at 3000+ at cruise to make the engine happy. What is his actual first gear ratio (first and rear combined) and what rpm will overdrive produce?

Devin

My car won't run below around 2800 RPMs. It likes 3000 to 3200 best on the highway. I can't use an overdrive transmission because of the cam. Better be sure that the gears will allow him to run at highway speeds and still let the engine run smooth. A 3.42 would probably be pretty good.

Is this for a 12 bolt? :confused:
If so, I've got a nice set of 12 bolt 3.31 GM gears available if interested...
i'll pass this on to him

He shouldn't have a problem I wouldn't think. I drive a 2.20/3.31 set up. It's not a rocket off the line, but if you've got enough engine once it gets rolling it should be a good running car.

A wide ratio Muncie, and a gear somewhere in that area should be good for daily driving. 3.36's and an M20 would net a 8.47 first gear. That should be pretty good gearing for a car that sees a lot of town miles. I don't know if that is his intent or not, but for me it works quite nicely. There is temporarily a Super T with a 2.64 first gear in the '70. That gives an overall first gear of 8.74. To be honest I wouldn't want much more gear than that for a car that is mostly driven on the street. But each person has their own preferences.
thanks for the reply
A couple of thoughts....If he is actually pulling the power he'd like, he's going to need to be at 3000+ at cruise to make the engine happy. What is his actual first gear ratio (first and rear combined) and what rpm will overdrive produce?

Devin
He will be building his engine to make that power.
His target is to cruise at 70 MPH at about 2000 RPM but thats after the OD gets into the car sometime next year.
My car won't run below around 2800 RPMs. It likes 3000 to 3200 best on the highway. I can't use an overdrive transmission because of the cam. Better be sure that the gears will allow him to run at highway speeds and still let the engine run smooth. A 3.42 would probably be pretty good.

i guess he needs talk to the builder about his RPM range and cam selection NOW??