You need to take a look at the GMPP Bowtie vortec heads.
Big 225CC port and small 185cc port. Ready to rock or bare.
This is the best true Vortec head on the market.
They are way ahead of the stock 062-906 truck heads and all aftermarket cast vortecs.
You and I own this company (thru your and my government)
You might as well buy their (your) products.
The price is right. North American cutting edge designed and made.