I have the opportunity to buy a 1969 Firbird Convertible that's been sitting in a garage for over 20 years. The car has a straight body and good paint, no rust. Clean interior and a decent power top. It has a 3 speed automatic. The only downside is that the original 350 was swapped out with one from a 1974 Lemans. Whats a fair price for this car? We were talking in the neighborhood of $10K before I discovered the engine had been swapped.
Where is this Firebird? Is it still for sale? Are you looking for investment or to cheerish personally? Me, if I had an extra 10k for a 69 Firebird convertible, in the shape you're describing, it would be sitting in my garage. But thats just me.
If the car is as good as you described 10K is not out of line even with a non original engine. You didn't say what othe options were on the car or what the factory color is. Both of those have as much weight, price wise, as the engine does. As long as it is a Pontiac engine and it looks correct, and you are looking for a driver (not trailer queen) don't let that engine scare you away from a good car. PS ,I own a '69 convertible with an incorrect drive train and there is no way I would sell it for 10K !!! 20K? Maybe.
While 10k seems to be a great deal regardless of the engine swap. Keep in mind theirs going to be some freshening up your going to want to do. Don't forget things always seem to cost more when finishing a car. An engine overhaul, new vinyl for the seats, kick panels or maybe a new paint job. All in all thats a good price and a good investment for what your describing.