Like previously stated, Nick does a really nice radiator. You can also pick up a 2 core aluminum rad for an F-body (90-92) for $189 from auto zone. You will need an external oil cooler though. Do a search for f-body radiator and you will find a better description.
Something else you may want to check into is Ramchargers dual fan setup. Basically it's two electric fans that fit the stock area that pull a lot of CFM, way more than stock.