wtf is your problem little kid?
everything is f*cking different... did you need someone to literally type that out for you?? was "honda and 4cyl are the only things that are the same" not clear enough???? the crank is different. the bore is different. the pistons are different. the rods are different. the entire f*cking block itself is different. physically and structurally. holy shit kid. even stupidstreet would tell you that in their amazing tech section.