Depends on the cam you have now and what you would choose to change it too! I haven't had an FE in anything for quite awhile, but one of the best pulling 390's I ever had was with a copy of the old hi performance 390 cam the Fairlane GT's had (335 horse cam?) with a fresh set of springs to go with it. If my (really poor) memory serves me correctly it was an Engle grind. Hard to answer your question without knowing the specs on the the rest of the engine.

The right cam and valvetrain in a good flowing set of heads can make all the difference in the world in the performance of the engine! and the wrong cam or mismatched components will instantly turn the engine into a pooch!!!!!