Dougs63

I'll be rebuilding a T-10 4-spd transmisson for my '63 Corvette and would like to convert it from wide-ratio gearing to a close ratio.

Are the parts available to perform this conversion and where would I find them?

Thanks in advance for any replies,

---Doug

Jackfit

I just have a question for you. Why are you converting from wide to close ratio.

From what I have read, the first gear on the wide will accelerate you more than the close ratio. For street light to street light racing, the wide was better. This fact was not really pushed, because if you compare the 327/350 wide Muncie with 427/425 with close, the wide got to 30 mph .25 faster. at 60 mpg 327 6.1 427 5.8 both cars had same rear.

You can find this comparison in Richard F. Newton's book,,, Corvette Restoration Guide 1963-67

Try to ride in a car with a close ratio and one with a wide and see which one you like better
jack

midyearvette

changing from a wide to a close gear set will definitely change the driving characteristics of your vette and maybe not in the direction you prefer or are looking for....what are you trying to accompolish??

Bob W

Unless you have a low rear axle ratio I would stay with the wide ratio trans. I have a close ratio box in my 57 and with the 3.08s in the rear it's a little tricky to get it rolling from a stand-still .

Bob

Glasshole

I have a close ratio in my 63 and was actually thinking of switching to wide.....Although I would like to try one first before making this switch.

*C7*

I changed my '63 from a close ratio to a wide ratio about 10 years ago.

Then last week I changed the diff. from a 3.70 to a 3.08.

I like both of the changes I made. I have owned the ole girl for 42 years and figured her racing days are behind her now.

Jackfit

C6 Z06

Hi, I have owned my 66 L79 since 69. M20 3.70 . Over 250,000 miles on it 4 rebuilds etc. This is the last one,, doing all myself except engine & paint . With the like new engine in it, (last rebuild 25 years ago and not a good one,) with no doors or hood , one seat in it , I took her out on the road.. I forgot what a 3.70 feels like when you have the HP . I got use to a weak engine and was put back in my seat by the newly rebuilt one. .... A great feeling but, not being 23 any more, and a 6,000 mile trip planned,,, I don't think the 3.70 will make me happy on long runs.. You put in a 3.08 .. are you happy with the performance you expected? Would a 3.36 be a good compromise? Let me know the results of your change.

Jack

midyearvette

difference from a 3.08 to a 3.36 is 2 hundred rpm in 4th gear however it is approx. 600 rpm in 1st gear!!..quite a difference...jmho

Glasshole

Is it just a matter of switching the guts inside the tranny or do you have to get a new tranny to switch from close to wide ratio?

wmf62

just the 'guts'. someone will correct me if i'm wrong, but i believe it just the input gear and the cluster gear that has to be changed.
Bill

*C7*

I am very happy with the 3.08. If I were going to take the time to change I would go with the 3.08.

I hate to admit it but I proably would have went with 2.73 or close if I could have.

It drives very nice with the 3.08 and has plenty of acceleration.

I'm 100% pleased with the 3.08s. Much less cabin noise at 75mph and runs smooth at 90mph. That is about as fast as I run the little girl.

Her younger brother takes over for her at that point.

Go for the 3.08s.

Larry.

*C7*

I agree with Bill, it is just the guts. When mine was changed from close to wide they used my original case. I thought all the gears had to be changed but I'm not sure.

If you have a shop that specializes in old 4 speeds do it they should have all kinds of good used gears laying around and would proably just do a swap plus a few bucks on the gears.

I had mine done about 10 years ago with all new synchros, bearings, gear ghange etc. for $330.00. I thougfht that was a very good deal.

Good luck with your choice, Larry.