According to the July 1, 1970 Pontiac parts catalog I have, the "69 F/8 400-4B.C." Hood Hinge Spring was part #546325. This was the only application for this spring, and it was NOT used for any other application and/or by another GM car division. It was discontinued as a service part April 1974!
To me the parts book application was a bit vague (as this occasionally happened), but I would guess this hood hinge spring was intended for 400 cars with the ram air inlet, and Trans Am. Someone mentioned once on this BB that Year One sells a reprint of the 1969 Firebird assembly manual. The exact application for this spring should be noted in there.
[ March 20, 2002: Message edited by: Pontiac Marv ]</p>