[unruhjonny]

/\ it that was in reguard to the RAIV part of my post;
To the best of my knowledge, you are partially correct;
The "1970+" Firebirds were not debut till February 1970, but the RAIV was from the onset, not officially an option;
Then add to the fact that it wasn't officially an option that (from my reading) it appears as though PMD actually intended for the Firebird (Formula & Trans Am) to use a different version of the RAIV engine - which used the RPO 'LS1';
From the September 1969 model debut of the GTO, the RAIV used RPO 'L67', just like 1967 RA(I), 1968 RA(I) & RAII, and the 1969 RAIV;
But the RAIV in the "1970+" Firebirds was supposed to be a different engine - and was not intended to take from the GTO 'L67' engines...
As I recall, the 'L67' engines were only "green lighted" for use in the Trans Am at around July 1970 after the 'LS1' engine program was officially moth-balled which is also right about the time the 'L67' Firebirds (all Trans Am's) were all built... this is why none were built before the tail end of the model year...

At least that is what I have read.

I cannot recall the sources I read that all in... but I welcome it being debunked.

I love the fact that one of the lead press cars for the 1970 Firebirds was a pre-production RAIV car...