You have the parts. If it were me I would deck the block and keep with the same plan.. A lot of the aftermarket are down .030 or better anyway. Boosted or N/A, still ideal to have quench. I have an engine waiting for assembly which we cut .052 off the deck to get it to zero.
I also have one Pontiac engine going together that I used 428 flat top pistons, DSS c/h 1.585, but have a 4.21 crank and 6.625 rods, .98 pin. No one had the pistons design I was looking for on one of the engine projects so I started with flat tops and machined a step type head. It is one of the engines getting the main cap girdle system. Might depend on the piston, but if the crown is thick, that is another possibility.
And yes...putting the blow thru carb in service sounds like a winning idea to me....
