What was wrong with the Olds engine?
Aluminum heads, what do those flow?
High RPM manifold?

I think your Firebird will be kinda heavy.
The Firebird hood alone is way, way heavier than my standard 69 Camaro hood.

I know my friends 69 Firebird weighed about 3800 + LBS 400 & TH400 trans.

I'll just throw out an ET guess for the Bird, 17.9 in the 1/4.

MBHD


12 port SDS EFI