Should I rebuild the muncie trans I have or buy a new one? Which is the better smarter thing to do? It is not the original trans so that does not come into play. I think some of my vibration is in the tranny. Any suggestions on where to buy new if that is the way I go. May want to go with the M22.

That's a very subjective question. Without having it in front of me, and having it disassembled, its impossible to tell what is "best". If it ONLY needed a rebuild with a rebuild kit, that would be the most ideal thing to do. Beyond that, it all becomes totally dependant on the condition of the interenals. If you do ALLLLLLLLLLLLLLLLLLLLLL the work yourself, and all that is needed is a rebuild kit, then you're looking at less than $200. Great deal! From there, parts, plus labor, if you have someone else rebuild it, can be $400-800. A professionally rebuilt Muncie (such as by Wally or myself) will be $800-1200, more for an M-22 and $1800+ for a BRAND NEW Muncie.
If your Muncie is working OK, that is, it changes gears OK, doesn't jump out of gear (such as 2nd or 3rd) when you let off of the gas and the main problem is a vibration, I'd suggest rebuilding it.
MOST LIKELY, if the only problem is vibration, then it will be coming from bad bearings, worn tailshaft bushing, worn driveshaft yoke, a combination or all of the above. All of the above, EXCEPT the driveshaft yoke, come in a rebuild kit.

what kind of vibe. are you getting? I have one that is only from 50mph on some slight vibe when accelerating hard in 2nd gear. I am going to try u-joints first & then maybe balance the 'shaft, If I still have a vibe I will have the tailshaft bushing replaced. BTW you didn't say WHICH muncie you had 20 or 21 ?

I have no vibration in neutral with the clutch engauged at any rpm. I have a close ratio pretty sure M 21. My main vibration is in 4th gear over 3500 rpm.

i have 1brandnew b/waner like m22 bolt on is remplement for muncie. bigger input shaft & output shaft you need fine splines cluth disc & t400 drive shaft yoke or i have 2 good m21s used muncie,s or make yours m22

at? what. spd mph

Speedo do not work. Supposed to be 3.73 but it may be 4.10. I looked at the trans and am not sure if it is a 20 or 21. 10 spline input and 27 spline output. I cannot find the serial number.

i have 1brandnew b/waner like m22 bolt on is remplement for muncie. bigger input shaft & output shaft you need fine splines cluth disc & t400 drive shaft yoke or i have 2 good m21s used muncie,s or make yours m22

This belongs in the Classifieds section!