[bill ryder]

Looking at 3, I believe to be, 64 Muncie 4 spds. One has no groove, one has one groove, and one has two grooves on the input shaft. Hopefully, someone can help me identify, or lead in a right direction!!!

THANKS

"Bill"!

[tempest1964]

Bill, here is a link from 5speeds.com :https://www.5speeds.com/casting.html
Paul Cangualosi is very good on these. As he has stated in his book and his videos, due to the age of Muncie transmissions, sometimes it’s better to look at the casting numbers vs looking at input shafts due to previous rebuild and mixing/matching of parts. He has a lot of good informational videos on YouTube as well. Good luck

[Baron Von Zeppelin]

Seems like the 64 units had a smaller diameter countershaft - shaft hole bore is smaller in the front of the case.
Something about them is said to be slightly inferior , I think that was it .

[Sunfirered64]

The case should help with the year, the last three digits are as follows
1963 case number 704 corvettes only as far as I have seen
1963 and very early 64 had case number 606 very rare case used in corvettes, never seen in a GTO by me, but 64 corvettes got them
64 case number 325 with pat pending very early cars before Jan 64
64-65 case number 325 with pat number
66-67 case number 010
68-69 case number 660
70-74 case number 661

always pop covers as even replacement Muncie input gears had no grooves
Muncie close ratio heavy duty (m22) had no grooves on production line, but no heavy duty 63-65 m22 build (save for a very few rare road race corvette) many 63-65 have no grooves, this is why you have to pop side cover
Muncie close ratio (m21) had one groove
Muncie wide ratio (m20) had two grooves 66 and newer

M20 and M21 are not exclusive to the Muncie as this is the GM RPO code and Saginaw used this as well (Camaros and non SS Chevelles and other GM's that used both cases use The M20 wide ratio and M21 close ratio for Muncie and Saginaw cases)

[60sstuff]

Mr. Sunfirered64,

If you have a Sunfire Red ‘64, would you care to post some photos.

Thank you.

[Rich-Tripower]

I'm not Sunfirered 64, but we have a Sunfire Red 64 and here are some pictures.

[Rich-Tripower]

And just for fun, a few pictures from "back in the day" (early 1970s) and one of the alpha and the omega (we own both).

[Sunfirered64]

It is in my trailer and in project state as we we just moved a couple of months ago. The house we bought shop is very small, so we will be building a new building here shortly. Then I can start to work on it again.

[george kujanski]

Chevy style muncies have the speedo fitting on the passenger side. Pontiacs have it on the driver side of the tailshaft housing.

Also the above comment was correct; the early units have a smaller countershaft; the later ones are 1" and better.

George

[Sunfirered64]

The speedo is mostly true, but the early ones all had the speedo on the drivers side up to the 010 trans 66 model year and then all had the passenger side once they went to the 661 case with the 26 spline input and 32 spline output.

[GtoFM]

Hope this helps. I didn't note the source