Kenny..I believe a 45* bevel on the plate-to-head buttment,similar to the Indy design, would be the easiest..and most efficient design for leak-proof sealing! The smaller the gap,the less sealent used= NO OIL LEAKS,OR SEEPING! I would keep it SIMPLE..ONE PIECE..more affordable! As far as the breather incorporated on the plate itself...EXCELLENT IDEA...as long as it's as efficient as valve cover breathers! Real glad you're working on this MUCH-NEEDED piece!