['ol Pinion head]

On the '73 M22 avail, basically drawing from several practical sources. One disassembling & rebuilding quite a few big output Muncies, two M21's which were original VIN matching out of '73 455 D-port T/A's. Have not had the opportunity to rebuild an original Muncie out of an original '73SD car, but hope that day will one day come.

Also have chased down big output M22's for close to 15 years. In doing so, have examined very many real '71+ M22's, & have never run across one with '73 features & Pontiac application VIN...this just strikes me odd. One would assume with 1420 455 D-port 4spd T/A's being built in '73 + the production of 4 spd SD cars, would have run across one...

Just went back through 1/73 dated master Parts book. Ck'ed countershaft & gear listings, no listing for M22 gears but listed M21 gears for '73 application.

To confuse matters more, just ck'ed '73 service manual & it showed basically same text when it came to describing the Muncie trans useage as '71 Pontiac Service manual, no where did either call the trans an M22, but can see how this could be interpreted for '73. The service manual can be interpreted several ways, it was after all printed WAY before production began. As a similiar flawed example of Service Manual info, the '71 Service manual lists a 4.33 gear avail optionally for '71 8.2 10bolt A-body use with close ratio HD Muncie. Even lists an axle ID code for 4.33 HD Safe-T-Track. Unfortunately, no such axle was installed in a production '71 A-body. This axle was cancelled along with several high compression engine options....the axle still made it into '71 Service manual, though, & we can see this info on several well put together internet tech info sites today.

Believe the book is still out on this one. About 8 years had a 4/73 or 6/73(?) dated Master Parts book, sold it to a SD restorer in CT, would love to see what that parts book, any dealer tech service bulletins & sales bulletins stated. Only have two contacts who own '73 4spd SD cars. One actually knows quite a bit about his car...very hands on guy. Will try & get his input as well.