Why was A1/L-75 Stage 1 not part of the GSX package?

I didn't realize it was only the Stage 1 non-AC GSX's that got the 3.64.

 

Nice finds!
Has to be the same car like said. The fender call outs only show one line as in GTO.

 

Back to the Buick GSX

This 2 page newsprint ad appeared in Chicago on Sunday, February 22, 1970

I spent about 3 hours piecing together the 2 pages and cleaning them up. But not too much! (think Jason's #508 GSX)

"This is Buick's GSX. Like certain other Buicks before it, it is anything but the expected. Who ever expected the Buick Riviera before there was a Buick Riviera? Who imagined two or three years ago that there would be a complete line up of Buick Gran Sports today? And who was ready for Buicks Opel GT?
And now the Buick GSX. Once again, Buick comes up with the unexpected. Just a few weeks ago the GSX was a specifically designed show car. Today, it's real and available in limited quantity at any Buick dealer.
So see the Buick GSX at the 1970 Auto Show. Get a good, close look at a Buick you didn't expect to see. And who ever thought you'd have a chance to drive one?
The Buick GSX. Another unexpected one from Buick."

 

The before on the pages I pieced together - if someone wants a shot at it:

 

Cool. I only have the 1 page version:

 

Thanks Gary! This is why I share. You get things back!