59er

Hi Guys,

I have had an inquiry from a fellow Aussie C1 owner and thought that I would throw it to the forum.

Here is his question:

Mark, I have contacted you once before and I wonder if you can help me again. I have the standard 15" rims on my stock 283, 1961 corvette with tall tyres but the diff ratio makes it hard to get going especially on a bit of a hill, I find I have to ride the clutch on my 4 speed gearbox a bit for the first 5-10meters . I drive the car everyday ie 20 minutes to and from work in normal traffic with the once a month highway drive. What ratio would you suggest for the diff? I would be prepared to swap my whole diff or buy another and sell mine in the future. Any suggestions?

Regards,

Robert.

Any help appreciated Guys and I will be suggesting that Robert join the forum.

kcust62

Mark,
Without knowing specifics, it sounds as though he might be running a 3.08 ratio, since he is missing the low end performance. An intermediate ratio such as a 3.55 or 3.70, might suit his requirements. My experience has been to go from a 4.11 to a 3.36. I sacrificed low end for better fuel economy and lower cruising rpm. The wife prefers to run 100 miles rather than the quarter mile. It made sense for me and works well.
Bottom line, he needs to decide exactly what he wants and do what will make him happy. Good luck!


[Modified by kcwild62, 7:52 AM 1/16/2003]

Plasticman

Basically agree with KCwild62.

I have changed from a 4.11 to a 3.55, and very pleased with the change. I am running smaller diameter rear tires (26.1" now vs. the standard 27.1"), so my "effective" rear end ratio is the same as a 3.70. I am sure I could of gone even further to a 3.36 (about the same as a 3.55 for someone running standard dia. tires), since I have come off from a stop in 3rd gear without much problem. Of course, I am also running a 355 CID SBC, which has a bit more torque than a 283.

Note that what trans he is running will also affect the ability to come off from a stop easily. Does he know if the trans is a "wide ratio" or a "close ratio"? Wide is better for starting off, and is generally used for tall gears, but if he has the close ratio, then that could explain things a bit. If he has the close ratio, and wants to stay with it, then definately recommend he go with the 3.70 rear gear.

Good luck,


[Modified by Plasticman, 9:56 PM 1/16/2003]

K2

59er;
Ditto on the Plasticman's tranny comment. The wide ratio transmission gives you the low gears for starting out without slipping the clutch and still allows you to keep fairly tall gearing in the rear which preserves your cruising speed and economy. I'm running the wide ratio with 3:55 in rear. This is a very good combination. Would also work well with 3:36 pr 3:08 rear gears. :cheers:


[Modified by K2, 1:07 PM 1/16/2003]

62fuelie

I have a 3.55 rear in my 62, but it is a fuel injected 327. I have even considered going to a lower (numerically) ratio. The 61 I had was equipped from the factory with a 3.70, which suited the 283 pretty well for all around use, but it is a little high for a lot of hwy use. I would be reluctant to put less than a 3.55 in a car with a 283, unless the 283 has a real mild cam. In that case a 3.36 might be ok, but I sure wouldn't go to a 3.08.