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Discussion Starter #1
Got a question for you muncie guys. What do I need to look for in a Muncie M21? Local guy says its out of a 1968 Vette, and has 18000 miles on rebuild. He says the ears are good and its in good shape, will get back to me with casting numbers. Remembered the thread about the tailhousing numbers, anything else I should look for? No linkage or shifter, will the one of the saginaw work, it appears to be an oem style muncie? Price looks good at 500.00



Thanks in advance, Sean:rolleyes:
 

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I have an M21 out of a 67 Z28 and a Sag out of a 78 Nova and the shifter mounted fine on both.

As far as the Muncie goes, prior to October, 1968 they do not have the letter stamped after the numbers to identify them as M20(A), M21(B) or M22(C) and the cover has to be removed to check the gear angle. The M-21 has a higher pitch angle on its gear teeth than the M20. Otherwise after October, you can just look for the letter code and verify the gear pitch.

You can also try this site: http://www.nastyz28.com/transid.html, but it'll pretty much tell you what I stated above.

Hope this helps some!
 

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The later muncies with the bigger 1" cluster shaft are supposed to be stronger. The M20 is a wide ratio trans, lower 1'st gear and more spacing between gears. M21 is close ratio, M22 is close ratio with the straight cut gears, they are not really straight but they don't have as much pitch as a M20 or M21 so they make a bunch of noise, thats why they call the rock crushers.

The rings on the input shaft do NOT tell what trans you have, you have to run the numbers cast into the case and look inside to see what gears are inside as they can be changed easily.;)

KenDog
 

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Discussion Starter #6
M21 Questions

Thanks for all the replies, I got some good data off the net and the seller is going to call me in the next 30 minutes with numbers. I'll check the casting codes and then go look at it in the am if possible. Do you guys think that $599 is a good deal if the gears are in decent shape. Thanks again

Sean

OK hell just called with the numbers, 3925660 and 385784, sounds like they'll work what do you guys think, and any tricks to checking it out. Thanks again:geek:




67 SS w 350
Sag 4spd with 410's and 14in ralleys
 

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$600 isn't bad unless you have to rebuild it.

I paid $750 for mine and another $100 to have it shipped, but didn't need rebuild.

If it needs rebuild, that's going to cost at least another $120, and that's just for bearings and seals. As much as $500 for complete gear set. Definitely make sure it's useable as is or you could be spending some money to make it useable.
 

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Discussion Starter #9
Thanks Kendog and Jade for the posts, I looked at the Z28 site and found the info--Thanks. I'll take a look inside the cover tomorrow, sounds almost to good to be true, I miss typed its $500. Guy seemed nice on the phone and he is always moving lots of car parts(musclecar) through the local paper. I'll keep you guys posted. Love the 4 speed, cant swing the five and the 410's are no fun with the little rims, oh well just shift and then drive 65 on freeway... But damn its fun getting there:eek:


Thanks again for the help, Sean
 
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