Thanks again for your info Dave !
" All those cars were Can Am, with shaker hoods & Opera side windows..."
Maybe we are not talkin about the same cars. The two that I know of were raced by Don Elgin & Don Turk.
The 1st pic below is the Don Elgin car. Looks to have a plain hood. I have it listed as a '75 model Grand Am.
The next pic is the Don Turk car. I have it listed as a '74 Gran Am, It appears to have the same hood as a '73 GTO. No shaker scoop sticking up thru either hood.
The only year model I've ever seen listed as a Can Am, is the 1977 model. They DO have a shaker scoop, which looks just like a Trans Am shaker scoop, as shown in the 3rd pic below. I've never seen one of those cars in Stock or SS competition.
The last pic shows the hood on a '73 GTO. Looks just like the one on the '74 Grand Am. But, the nose & grill are different on the GTO.
This article says that GTO hood was optional on the '73-'75 Grand Am.
http://www.tachrev.com/GrandAm1973-75.htm
Here's more info on the Can Am.
http://www.tachrev.com/CanAm1977.htm