You seem to be under the impression that 350 chevy and 350 pontiacs are interchangable motors. They are not. There are alot of differences. That's why crazy says it will cost you alot more. Because you will have to gather alot of stuff to go back. You will be much happier(my opinion) if you do and 325hp is easy to achieve even with a fairly stock 350 Pontiac motor and you will have alot more torq. Of course you're likely to spend more money on tires but such is life owning a Firebird.