1973 Trans AM Tranny Codes

[73 Muscle]

Newbie here. I am one of those lucky people that own (2nd owner) a 73 true Brewster green T/A which is currently undergoing a frame-off restoration. The numbers matching 455 engine and the differential have been rebuilt. As I was examining the TH400 trans my heart sunk after discovering that it was not numbers matching. It came off a 78 Oldsmobile. 

I realize that I will never find the original tranny but would like to install one from a 73 Firebird/Trans AM. I am by no means an expert but did some research pertaining to the 73 Pontiac trannys and found out that the plate/tag that is riveted to the case should read 73-PQ. The “P” is for Pontiac and the “Q” is for the A & F series, 455, 4BBL SD, Firebird, Le Mans & Grand AM vehicles. Also found out that a 73-PR tag reflects a 73 TH400. The “P” is for Pontiac and the “R” is for the A & G series, 455, 4BBL, Firebird, Le Mans & Grand AM vehicles.

Based on my findings, both the 73-PQ and 73-PR TH400 are compatible with the Firebird, which is confusing.  Can someone advise me if my findings are accurate and what the correct tranny code would be (73-PQ or 73-PR). Also, is there anyone out there that has a 73-PQ or 73-PR core or case for sale?

Thanks     

[Ringo64]

Unfortunately, I do not have an answer for you on your question. However, if you would like to post a Want to Buy (WTB) listing in our Classified section for the part(s) you need, that may be a good idea: https://foreverpontiac.com/classifieds/

We'd also love to hear what you've done so far with the TA, you can detail your progress if you'd like in our Progress forum with your own topic: https://foreverpontiac.com/forum/9-pontiac-progression-place/

Look forward to seeing you around!

[Frosty]

Hi 73 Muscle - Welcome to FP.

You are looking for the 73-PR transmission case. That is the proper case for the standard 455 for the Lemans/GTO, Grand Am, and Firebirds, These are the A&F bodies only. The Grand Prix did not get the 455 in '73 and it's transmission case was 73-PX.

The 73-PQ case was reserved for the Super Duty A &F bodies (which as we all know was only put into the Firebirds even though the '73 SD GTO was made Car of the Year but was never built).

My information comes from:

https://www.tpocr.com/pontiactc.html

 

[73 Muscle]

4 hours ago, Frosty said:

Hi 73 Muscle - Welcome to FP.

You are looking for the 73-PR transmission case. That is the proper case for the standard 455 for the Lemans/GTO, Grand Am, and Firebirds, These are the A&F bodies only. The Grand Prix did not get the 455 in '73 and it's transmission case was 73-PX.

The 73-PQ case was reserved for the Super Duty A &F bodies (which as we all know was only put into the Firebirds even though the '73 SD GTO was made Car of the Year but was never built).

My information comes from:

https://www.tpocr.com/pontiactc.html

 

Very useful info. Thank you. I've started my search for a 73-PR case.

[73 Muscle]

5 hours ago, Ringo64 said:

Unfortunately, I do not have an answer for you on your question. However, if you would like to post a Want to Buy (WTB) listing in our Classified section for the part(s) you need, that may be a good idea: https://foreverpontiac.com/classifieds/

We'd also love to hear what you've done so far with the TA, you can detail your progress if you'd like in our Progress forum with your own topic: https://foreverpontiac.com/forum/9-pontiac-progression-place/

Look forward to seeing you around!

Thanks Jim.

I posted a WTB listing in the Classifieds. Hopefully I'll receive some good news. I'll work on putting together a progress report.

[Frosty]

Good luck. 73 Muscle

we like to hear the trails and tribulations of restoring or hot ridding a car. I am willing to share my triumphs and oh-sh*t moments with the folks here. That way we all learn together.