Can i run a flat tappet cam and lifters in a block that came with roller lifters from the factory? would there be a push rod change if so? And what kind of luck have you had with running an electric fuel pump for a carbed engine?

I found a crack in the block of my 86 4.3V6 after i paid a machinist to flux it, already bought the parts and cant find a replacement block. The machinist is willing to give me a later model roller block and the fuel pump boss is not drilled for the pump shaft.


1986 Monte SC. 4.3 TBI V6 with Vortec heads and a Luntani cam backed by a WC T5 and 3.42's outback.