Muncie M21 dated P9B17

[rlw68]

Looking for original M21 for my 69 Z/28. The protecto plate has trans assembly code P9B17.

Yea I know this is a long shot...

[enio45]

is that , i assume a late car? Would it have an A, B or C after it, if it was late production?

[rlw68]

Originally Posted by enio45

is that , i assume a late car? Would it have an A, B or C after it, if it was late production?

The car was built in February. Should the stamp on the trans include the B code for M21? It has the original engine and rear axle (4.10!)

thanks,
Rob

[Steve Shauger]

Rob, the letter suffix stamped after the assembly date on transmission denoting A=M20 ,B=M21,C=M22 is not designated on Protecto plates. Your Z28 could have come with any version trans, but the most probable is M21, so percentage wise Bor M21. I've owned/own Z's with all three configurations. Early 69 built cars with muncie trans didn't have the suffix stamped but based on your build date it would have.

[Steve Shauger]

Just to clarify, Muncie transmissions built after approximately Oct 20th of 68 were stamped with the suffix trans designation A, B & C

[big gear head]

Mine missed it by 3 days, right?

[Mr70]

Yes

[rlw68]

Originally Posted by big gear head

Mine missed it by 3 days, right?

Thanks for the pic! Where is the partial VIN stamped, assuming this is in a Norwood car?

[rlw68]

Originally Posted by Steve Shauger

Rob, the letter suffix stamped after the assembly date on transmission denoting A=M20 ,B=M21,C=M22 is not designated on Protecto plates. Your Z28 could have come with any version trans, but the most probable is M21, so percentage wise Bor M21. I've owned/own Z's with all three configurations. Early 69 built cars with muncie trans didn't have the suffix stamped but based on your build date it would have.

The options on the sales doc has '4-speed trans' separate from 'Z28 Equipment'. Thats interesting since the 'rear axle ratio' listed by itself is for the 4.10 gear. Would it be common to use the M20 or M22 with this setup?

[big gear head]

Originally Posted by rlw68

Thanks for the pic! Where is the partial VIN stamped, assuming this is in a Norwood car?

When I had this transmission out I didn't look for the VIN. It's been buried in a cabinet for a few years and I would have to dig it out to check. I took it out of a '67 Chevelle that I bought years ago.