gears

[xxslow50xx]

for the cv im guessing from what ive read the best gear to go with is the 3.55s i have 3.73s in my mustang and its not bad on the freeway im getting 22.5 miles per gallon now with my 2.73s would the 3.73s kill my gas milage that much or no, or should i just go with 3.55s

[Mr. Land Yacht]

well...
I get about 21.7mpg on the highway with my 3.55's.
you prolly wouldn't notice much difference in MPG with 3.73's but the acceleration would be a little faster.
however, I'm thought I read somewhere that with 3.73's, you should get an alluminum Driveshaft to cut down on the vibration at highway speeds...
in that case, I'd suggest the 3.55's.
when I had my differential changed...my 0-60mph time went from about 12.2 to 9.3!

[Nathan in MI]

I'm not sure how much difference it would make in mileage, but since you have a 351, your engine has more torque than the average 302, so you probably don't need 3.73s. I think you'll be pretty happy with 3.55s.

[88Vic]

The 351's don't have that much more torque and HP than the 302. Mike says he gets decent mileage with the 3.73's in his wagon. And if you can find an aluminum driveshaft that would helf even with the 3.55's if you go with them.

[mrltd]

I get 22 mpg in my wagon with 3.73's....

[Nathan in MI]

I get 22 mpg in my wagon with 3.73's....

But keep in mind that you have a fuel injected 302 and he has a carbureted 351. That high of a rear axle ratio with that engine, if you're concerned about mileage, doesn't seem like the greatest combination to me.

[Blaze86Vic]

Go 3.55. A carbed 351 has its power at low RPM, not high RPMs. You will benifit most by not having such a tall gear. I'd suggest even lower than a 3.55 if you care about mileage. I myself plan to go from a 3.55 to a set of 3.31s that I have, more for the fact that with 3.55s top speed is RPM limited to 115mph. But I'm also just preaching to the quire.

[xxslow50xx]

so i think im gonna go with the 3.55s because i wanna keep gas milage and i want some more pick up out of it. what gear do i need to keep the speedo right?

[Lincolnmania]

i get 22 mpg with the 3.73's in my towny

[DuceAnAHalf]

Ive got 3.55s behind my 351, i get about 6-7 MPG in the city, about the same on the interstate.

[xxslow50xx]

wow thats some bad gasmilage man right now im getting at least 12-14 on the streets and 22 on the freeway i relly dont think my gas milage will get that bad if i go to 3.55s unless im on it everywhere

[DuceAnAHalf]

wow thats some bad gasmilage man right now im getting at least 12-14 on the streets and 22 on the freeway i relly dont think my gas milage will get that bad if i go to 3.55s unless im on it everywhere

Ive also got a 3-speed, plus my car is built for power not economy.

[mrltd]

He also has a 3000 Rpm stall converter, so it never locks up during normal conditions.

[DuceAnAHalf]

He also has a 3000 Rpm stall converter, so it never locks up during normal conditions.

It never locks up, C4s dont have a lock up function