Author Topic: M20 or M21  (Read 2635 times)

ericisback

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M20 or M21
« on: May 24, 2020, 03:04:53 PM »
I think I know the answer to this question, but never hurts to ask.  Is there anyway to know if this is an M20 or an M21 from the attached photo?
67 Corvette 427 conv. -  https://bit.ly/2yykRW7
67 GTO 400 conv. - 68 Camaro 396 conv.
69 R-Code Mach 1 - 78 VW Beetle conv.

WorkinProgress

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Re: M20 or M21
« Reply #1 on: May 24, 2020, 03:12:28 PM »
Is there any ring grooves on the input shaft?

                          - Warren

z28z11

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Re: M20 or M21
« Reply #2 on: May 24, 2020, 03:32:42 PM »
You can see one groove, there is a suggestion of a second groove (which 2 would denote an M20), but it's not clear. If the pic was shifted forward about an inch you could likely see for certain. You know it's a 1" cluster pin Muncie, '68 likely.

Doesn't appear to have a suffix on the build code, looks like an "8" to me. What an eye - stretching exercise -

Better pic of the input and you can figure this one -

Regards,
Steve
1968 Z28 M21/U17 BRG/W 1967 Chevy ll Nova SS 
1969 Z28 X77/M20/VE3 LeMans/W
1969 L78 X66/N66 Cortez/BVT
1969 Z11 L48/M35/C60/C06  1949 3100 5wd 235/6

ericisback

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Re: M20 or M21
« Reply #3 on: May 24, 2020, 03:34:42 PM »
Is there any ring grooves on the input shaft?

                          - Warren

I only have the photo.
67 Corvette 427 conv. -  https://bit.ly/2yykRW7
67 GTO 400 conv. - 68 Camaro 396 conv.
69 R-Code Mach 1 - 78 VW Beetle conv.

 

anything