Stock Vortec heads are good to about 5,200 RPM and then they go flat. You can not run a high lift cam (anything over .480-.500) because the valve spring retainers will hit the valve guides. You can machine Vortec heads for high lift cams and better valve springs but after you have paid for this aftermarked performance heads start to look affordable to.

I like Vortec heads. I have a set on the motor in my roadster. These heads complemented my over all build plan. A simple motor for street use. One that had good torque and power from zero to 3,500 RPM, the range that I drive in 99% of the time.

I used a tight quench (.038, about as close as you want to go on the street), and Edlbrock Performer intake and matching cam. I recon I have 300 hp. Nothing to brag about. But I run all day on 87 octaine and I can get rubber off the line and a nice, satisfying cherp going into second.

Built some radical motors in my younger days. Most of them were expensive mistakes.