W2/W5/R3 Engine Build Opinions Needed

I say start with a good foundation no mater what so number 3 should not be considered. I have big dollars in my stroked 340 with Indy heads now I want more than my 550 HP but am a little afraid of pushing a .040 over production block. Wish I would of started with a better block. Now I have to spend more money for better block and all the machine work again.