Bobby,

 I agree that the exhaust ports could be smaller, and I think it may help the flow stay less turbulent when it exits the block, I stayed with the larger openings, due to the exhaust manifold gasket. I intend to use the factory gasket, as I didn't know what else to use. Obviously the factory gasket has the large openings. (as a matter of fact, the intake and exhaust flanges that  Tech welding sells were patterned off of my gaskets)

Interested to see what you come up with. Keep me posted.

Ben