I have a 1990 Pontiac firebird, and the gap on that, I believe is .035. If you still have the sticker under your hood with the engine size, it says it right on there.
It is listed in the 1991 Pontiac Firebird Operations Manual
What parts??? Body, engine, suspension???
I calc'ed my '91 V8 Formula Firebird to be about 18 mpg.
i know the backs are 6x9
A firebird can't "have" third gen. It either is or is not a third generation firebird, and Yes, a 1991 is a third generation.
underneath the drivers door
I know mine is on the drivers side there is a door in the kick panel
I use 10W-30
A wiring diagram, for a 1991 Pontiac Firebird, can be obtained from most General Motors dealerships. The wiring diagram can also be found at most auto-parts stores.
Roughly 4.5 quarts with a filter change.
It's under the car in the middle in front of the fuel tank
10w30 motor oil should work nice