[BBIGG BLOCK 396]

Only way to tell for sure is pop off the side cover and look at the cut of the gears,there is a web site on muncie transmissions that will show you the difference in the gears on a M21 and a M22.A lot of M21 trans used the same cases as a M22.There a lot of indications to look for and your trans has all the indications as being a M22! but the only way to know for sure is to look at the gears.

Bobby Dodson