Like cs19 said...you won't be dissapointed. It is a great combo, I did a 496 last year Dart heads/manifold with a pretty healthy cam (wet exhaust with no reversion) and I dynoed at 598 hp on pump gas, nothing exotic at all, no porting on the Darts (FYI-I have owned some other aftermarket heads and I am very impressed with the Dart head/manifold combo)
If the motor is coming apart do it!!!
what compression?how big was the roller?