[Chevelle-List] vortec heads

[Mabs, Kenneth]

I need some help with finding a way to use a strong cam with L31 vortec heads.  I just ordered the heads and need some imformation on how to use a strong cam with a higher lift.  The heads are said to be capable of handling only up to .470 valve lift but i was going to use the edelbrock performer RPM cam which has a .488 intake and .510 exhaust valve lift .  I have a 350 4-bolt, performer rpm air gap intake, L31 vortec heads, and an edelbrock performer series 750 carb.  I want to run around 400 hp but that would be harder to reach with a small lift cam.  Are there any modifications such as umbrella seals that i could use so i could hold a more mild cam than stock?    ken mabs 70 malibu 350