If you want a better range of value, sign up at TAC,
www.transamcountry.com. We have several guys that can pinpoint, usually within $500.00 what a car can/will sell for.
After viewing your pics, I'm gonna stick with my first thoughts. It's a very nice driver but the unoriginality hurt the value, even with the original drivetrain. Remember, the hardcore Firebird guys WANT the origianl drivetrain, and will pay a premium for it.