Yeah that would be VorteC, not VorteX. Produced in 1996 -2000 GM truck (L-31) applications. MAX lift is 0.43" as stated. The valve spring retainer hits the top of the valve guide if you try any more lift (destroying the seal and causing all sorts of valve train damage) The press-in studs are notorious for pulling out of the head on the Vortecs, and that is all assuming they are not cracked. The L-31 head was a great head,, 15 years ago. But they were a part of the GM 'less casting is better' (cheaper) being a lightweight thin casting and unfortunately the Vortec is akin to the ancient 'camel hump' heads of the 60's. Just NOT the ideal find they used to be. If you have / find a set, and having them totally rebuilt (assuming they are not hiding cracks between the exhaust seat the the coolant passage) Your going to spend as much on rebuilding them with new valves/ replacing and cutting the guides / springs / seals / milling.. the Aftermarket offers a much better head for less than you will spend 'fixing' a 15 year old used casting.
If your happy with your Edelbrock carb, then you should continue to use it.
I would have to disagree with a couple points gofast...
I've have ran Carter AFB's and Edelbrock 'performer' (simply a Weber produced clone of the AFB that Edelbrock puts their logo on) Yes there is a lot of brand loyality in carbs, but no one winning races is running a Edelbrock carb. They appeal to the "bolt it on and forget it' crowd like showcars and those that dont want to (or know how to) tune the things. I mean seriously,, how many people spend the $69 for
the Edelbrock 'calibration kit' and it conveniently leaves BIG gaps in the provided jets and rods so you have to order additional metering rods to 'really' get it right. There pig fat out of the box, and most people are happy with that.
AND increasing gasket thickness to reduce compression on a detonation prone combination is really a BAD idea. He is calling out a 0.015 deck clearance, and a 0.039 gasket is already a 0.044 quench. Real close to the 0.045" quench ( 0.025 stock deck clearance and a 0.020" steel shim gasket). A large qench is a source of detonation to begin with.. Adding quench space by adding gasket thickness is really counter productive to solving the problem of a BAD combination of parts.
That said..
We absolutely agree he's going to have issues with this combination of parts. Too much compression, (just FYI contrary to common terms, Overlap doesn't bleed off compression and there is no pressure built during the intake stroke. It's the late intake valve closing that reduces cylinder pressure at the cost of low RPM torque, but I know what you mean) And trying to find a cam that offers enough duration to that end,,,, and not exceeding his lift limits on stock Vortec's,,, he has a tough ahead of him!!!
But BEFORE the build is the time to discuss things like this... How many have we heard that build with a combination of popular parts from the latest rage in the Chevy magazines,, hen come asking WHY is my motor such a gutless, detonating POS?