What's the real story with vortec heads?

Scoggin-Dickey says they can't take over .450 lift, but they want to sell their modified heads with Z28 springs and LT4 retainers.

GMPP uses a .435/.460 lift cam in their 350HO crate motor.

Chevy High Performance says max of .470 lift.

I want to use Comp Cams 265 Dual Energy .442/.465 lift or XE262 Xtreme Energy .462/.469 lift. Will either work?

What cams have you people been using with Vortec heads?

Thanks,
Joe

PS Is it the springs or the guides that limit valve travel? If guides, can they be hand worked a little?

Hey Joe, I wondered the same thing myself ever since you posted this question. Chevy high perf. magazine April 03 pg.21 Dept. of Corrections states that the max lift for vortec heads is .470 as long as you don't float the valves. But .470 inch lift squeezes the retainer to valveguide seal clearance to less than the recommended .050 inch. So I quess if you are going to push your engine much past the 5700 rpm redline I would get into some machining work.
I am looking for a roller cam to put in this engine that operates from idle to 5000 rpm range that produces gob's of tire frying torque in that range. The cam that's in there now is good for mid to high end power...but I want something more for low to mid range for messing around at street lights. If anyone has any good specs for a good "torque" cam i'm all ears.Feel free to e-mail me.


Sarge

Actually, you could get the Vortec heads and change out the valve springs for ZZ4 units, that are good to .525 lift. That would solve your problem. You can usually find the valve springs listed on eBay for under $50.