muncie identification and more

Hey guys, so awhile ago i was researching which muncie we had in our GTO project. After some reasearch i found how to identify it. Unfortunatly i have lost the paper i wrote the info down on. Here are the casting numbers

Front half of housing is 3885010
Tail housing is 3846429
Date code is P1116

So from the date code i know the tranny was built before they used letters to identify the muncie type.

If im reading the codes right the P1116 means it was built by muncie on sixteenth day of the eleventh month before 1966. Unless that finnal 6 is a G and im reading the code wrong.

Also the front housing casting can match a
M-20 M-21 M-22

The rear housing casting matched up to a 65 and the front housing matched a 66 casting. Did i get a website that had miss information?

Please help me identify my tranny im trying to figure out how its going to work gearing whise, now that i finnaly got a good speed calculator.

P.S. Jim, i finnaly found out what heads we have. We have 15 D-port heads that have been worked up to 2.11/1.77 valves.

I also have a new concern. I went to a local Pontiac club meeting and right away the speculators attacked our project, claiming that a 455 bored .060 over was going to have to thin a cylinder wall and will lead to hot spots then eventually catastrophic engine failure. What do you guys think?

To refresh everyones memories were building a 65 GTO with 455 12.5:1 C.R.
.060 over and with a lunati bracket master cam. The pistons were turned around 180 degrees. Balanced, blueprinted,shot peened,decked,bored,and heat treated.

Also we have a 389 were building with the 3x2 setup, we still need one more end carb before the rebuild process. HINT HINT let me know if you have one.
Thanx guys and happy building.