I vote for the stock manifold for milkd boost applications. You can have the manifold extrude honed can't you. It's durable, cheap, easy to find, and hardly any fabrication required for a turbo to work with it. Seems logical to me. Good luck. John.

'68 C-10 - 250 with Edelbrock 600cfm 4 barrel, Offy intake, Hedman headers and true duals, HEI, MSD 6A box, relocated gas tank
Soon to have: T-5 tranny