Hi guys,a have a 55 inch blackjack and a very mod zenoah g260 pum engine,this is my question,wich pipe should i use, 2\" band or standard,i have both.this engine has a light piston,257 carb,full port job,including the casing,crank has turbos,high timing and alow squish.the header is a 90 degree 3\" .please help me out,.thanks

Big boats require more torque from engine than smaller boats.

I would suggest a BANDED pipe like a NFS 2 inch band steel, The CC racing 1 inch header 2 inch band aluminum or the old standby .... Midwest 2 inch band aluminum.