"no one" wrote in message
...
I'm wondering what are good price/performance modifications for this
motor
(1997, in an inboard ski boat). Specifically, what modifications that
would
commonly find on street of off road vehicles, such as heads, cam, MPFI
kit,
intake manifold, supercharger, etc, would not work or not work well on a
marine engine application? Obviously exhaust is one of them.


What ever you do to it, is never going to justify the expense. Its a Ski
Boat. Their hulls will only go so fast.


Secondly, how will the existing fuel system cope with additional
horsepower,
or is an aftermarket open loop MPFI system one of the required
modifications?


It won't! you are going to be reprogramming computers, and maybe changing
injectors and increasing fuel pressure.


The boat has enough low end for my purposes, so I'd like to bump the
power
range to 2000-6000rpm and get another 5-10MPH (70-100 hp?) out of the
boat.
(Let's assume it is or will be prop'ed appropriately)


100 HP in a ski boat hull is probably not going to gain you 10 mph. Check
out what speeds are run with a 320 HP engine and then a 400 HP engine.
Its only a couple MPH. To gain 100 HP on a SB Chevy, you are going to
have to change the cam, change and/or port the heads, reprogram the
computer, change the exhaust, and change the fuel system. You are
talking thousands of $$$ here, and when you are done, its gonna be a lousy
ski boat.