reedkona

I'm getting ready to put the parts from the basket back together on my '63 swc. It is an early car (Oct. '62) 340 hp car with close ratio T10 and original 4.56 rear. I'm not sure what to expect with this ratio, since this car hasn't been mobile since I've owned it. My '59 has a 3.70 posi and a Muncie in it now behind a 327 with 3 rochesters (the matching number stuff is on the engine stand) and it goes like stink and is not running at high rpm at highway speeds. Just how high revving is the 4.56 and cr T10 combo?
reed

LouieM

I once had a 63 fuelie that came, used, with a 4.56. Man, that car sure was fun in town, at least for a few months. The noise (and thoughts of engine wear) made me crazy on the freeways, though. I swapped another guy who had a 3.70 and we were both happy... he had a Traco race motor in his 67 and it liked the 4.56 better.

MikeM

Depending on tire size, every 600 rpm equals 10 mph, roughly.

I've never been to Hawaii, but just from looking at the pictures, I can't see you overreving the engine on those roads.

If you live in the wide open spaces, flat ground, daily driver, the 4.56 wouldn't be my gear of choice. I ran one in my daily driver for a number
of years though.

Donald #31176

Assuming a 26" tire diameter and 3000 RPM with a 4.56 ratio you will be going 50.6 MPH.
With a 3.55 ratio @ 3000 RPM your speed is 65 MPH.

Ron Miller

For a daily driver with a combination of local/highway driving, I prefer a 3:36 rear, assuming no O/D transmission has been installed.

Anything from the 3:70 to 3:36 should work fairly well, just depends on what you're looking for. And, just my opinion . . .

JohnZ

With stock 27" tires, a 4.56 will give you 17.6 mph per 1000 rpm.