Transmission ID and Gear question
 

With our car on the lift I was able to ID two numbers off the transmission.

P 05 16

3115968

I'm hoping these can confirm what I think is a Muncie m-20 in our 1963

If so how do I know what the ratio's of the tranny are?

Also, I've posted about changing the rear end ratio to a 3.36 or a 3.55.

Where is the place to buy quality gears for the rear end??

Thanks

Don

The P0516 is the Muncie date code. P numbers from ’63-66 included only the month and day so yours would indicate May 16. The 3115968 looks like the VIN derivative. If your car’s VIN is 115968, it’s the original transmission. No way to tell from those numbers if it's an M20.

Ha! I'm so stupid. You would think I would recognize my own VIN by now.:eek: Shows what a newbie I am.

Yes, that is correct. My VIN is 30867S115968 and the B-Day of my car is estimated as May 27th 1963

That is awesome:thumbs: my tranny is original.

So the next question is how do you tell the gearing in it?

M20s in 63 were the following
1st....2nd....3rd...4th
2.56, 1.91, 1.48, 1.00

My car was built the next Day May 28th 116011 Lets see a picture of yours

PS- May 27th was Memorial Day so GM was closed so your car was likely built May 24th not 27th
Punch in your last 5 here http://www.stl-vettes.com/65Vette/bday.htm
Heres mine

The odds are that it is a M20. I looked at my Black Book and it shows 17,973 M20’s produced in ’63 and lists no M21’s.

Since a lot of these old transmissions have had gears replaced, the only way to know for sure would be to use one of the Muncie reference sites like: http://www.5speeds.com/muncie2.htm , open the side cover and count teeth. :thumbs:

Mike67;

thanks for the great resource on the Muncie. The tranny is coming out and I will be able to run down all these numbers and determine exactly what is inside. This is great fun learning new things and getting the car exactly right for our intended use.

Again, where to buy quality rear end gears?

www.bairs.com Yogi usually has a good selection of used GM ring & pinion gears, which are better than any aftermarket gears.

The customer had no choice in transmission gear ratios in '63 (or '64-'65 either); the engine dictated whether you got a close-ratio or wide-ratio transmission. 250 and 300hp got wide-ratio, 340 and 360hp got close-ratio.

There was no such thing as M21 on the order blank until 1966. :thumbs:

Thank you John Z!!!!

As seen in the pic. My car had the shifter replaced. While the tranny is out I would like to replace this shifter with the correct one.

I saw in another post that you confirmed that a 1963 shifter was a "one year only part".

Can you or anyone guide me as to what is the correct shifter unit to purchase?

Best

Don

Paragon has the '63 4-speed shifter - their #1553. They also have the linkage kit (rods, levers, clevises, etc.), the rubber boot, bolts, etc. Photo below shows the '63 Muncie setup - yours may look different if it's all Hurst parts. :thumbs:

JOHN Z does it again!!!!:rock:

Just to be sure as I know there are a lot of exceptions to things.

My car is a late 63 with build date of May 24th so all 1963's had the shifter you site above?

thanks so much for pointing me in the right direction.

Don

Yup. :thumbs: