Found the rattle in my 454, gen 4 motor. It was one of the flappers. It rattled like a bunch of bolts in the engine. I built the 330 peanut head motor to 262 large oval port heads (70 corvette heads) wich raised the compression to about nine to one. Added a crane cam with 529 lift with 1.7 crane gold rockers, 3/8 pushrods, double roller chain, Performer rpm intake with Holley street avenger converted to marine use. My question is can I leave out the flappers in the y-pipe? Will it flow better? Do I have to worry about water reversion?

I don't run them and my crane cams are bigger than yours. .630 lift