At the risk of stirring the pot... Ram Air IV was introduced in '69, and about 88 Firebirds had them, mostly T'/As. The "round port" engine in '68 GTO was called "Ram Air II" (the '67 GTO had "Ram Air I"). The few '68 "Ram AIr" F-bodies I've seen were the 400 with #16 heads (D-ports). If they put the round port motor in the Firebird in '68, I have not seen one.