1973 SD Transam 4 spd 1 of 72 built

[iluv69s]

Really love the early TA's, but I'm naive about these cars.

ram air delete?? were they all that way?? Is car stripe delete or did they not have the stripe in 73?
GLWS

[njsteve]

No stripes after 1972. Ram Air Delete refers to the mandatory block off plate riveted to the back of the shaker instead of the solenoid operated flapper door. Drive-by noise regulations in 1973 mandated it. Owners simply drilled out the three rivets and the shaker was then open. Very rare to find an unaltered original shaker with the rivets intact these days.

[Postsedan]

A beautiful example.....I love the White

Dan

[ruc]

Would love to have it!
Would make a nice mate to my Polar white/red 70 Judge.
Great Car

[black69]

Another point of information is this car has a close ratio 4spd (few made?) and has the more desireable rear end ratio (3:42). This car would be in the 13 second range which was amazing for 1973. On the other hand, a 73 SD w/automatic with air conditioning would have a different rear end ratio (3:08) that would put it at a disadvantage. That version would be in the low 14s.

Not all 73 SD 455s Trans Ams were created equal. This is one of the fastest ones that put it into the performance range of 70 hemi cars, etc. which was just mind blowing for the times.

The more I learn about this car, the more I like it....

[njsteve]

3.42 was the rear end ratio for stick cars and 3.08 was for the automatic cars with or without A/C. (No A/C allowed in stick cars). All the four speed transmissions were the same internally and were no longer built by Muncie in 73.

You are quite correct- these cars are scary fast. And to think that they accomplished all this with 8.6 to 1 compression!

If there is one version to have of a SD455, it would be a stick car. (Unless you're old like me and need to be refrigerated and have the shifting done for you) :-)

[Gary Anderson]

"All the four speed transmissions were the same internally and were no longer built by Muncie in 73."

Can you elaborate on this? I thought Muncie's ran through mid year '74?

[njsteve]

Sorry about that, my typing overtook my memory recall ability. The close ratio Borg Warner Super T-10 started in 74 and was used in the 74 SD455 cars. The SD455 still had Muncies in 1973 but if I recall correctly, it was the M20 wide ratio. The regular 455 got the close ratio M21, (the M22 got dropped after 1972).

BTW, all the transmissions used the "M" in front of the number regardless of who made them (not just Muncie) and what year.

There's some SD455 trivia on the trans question half way down the page here: http://www.angelfire.com/mi/jamos1/sdtrivia.html

[KenMaisano]

Originally Posted by njsteve

3.42 was the rear end ratio for stick cars and 3.08 was for the automatic cars with or without A/C. (No A/C allowed in stick cars). All the four speed transmissions were the same internally and were no longer built by Muncie in 73.

You are quite correct- these cars are scary fast. And to think that they accomplished all this with 8.6 to 1 compression!

If there is one version to have of a SD455, it would be a stick car. (Unless you're old like me and need to be refrigerated and have the shifting done for you) :-)

I'm one of the old guys, I had a 74 Four speed and sold it. And bought a Auto A/C Car.

[The Boss]

Damn!