ADVICE on 454 Gen V
 

Because of size of water jackets, extra large, I was told my gen V 454 efi was a poor motor to upgrade for more power, my engine builder says to easy to waste head gaskets because they are so close to pistons. He also said these gen V were only produced for 19 months then replaced by gen VI. These motors have small & M 250 blowers and performance was supposed to be upped by 100 hp performance is bland. 34' Magic, 7400 lbs. plus 180 gal of fuel top end 71 mph. The laptop records 4900 rpm with 30 x 15 1/4 bravo one 4 blades. Need more power but don't want to invest money in engines if he's right, he says build new. Am I expecting to much from these motors? Any suggestions? Thanks!!

Is your motor 7.4L or Magnum? If it isn't a mag, you should probably get new motors. It is my understanding that the changes from gen v to gen vi is minor. I'm pretty sure water jacketing isn't changed. things like roller lifters, front cover, no fuel pump mount, stuff like that. Hope that helps.

454 efi Magnum

I don't know of any reason you can't build those motors. I'd be looking for other builders.