Unitek

I just picked up this boat, http://adcache.boattraderonline.com/6/9/4/80272694.htm
and I want to mod it up some. not real sure what series the 454 is but it has low hours and is 100% stock. looking to spend like $1500.

Thanks,

Mike

cstraub

$1500 is tight budget even if you are doing it yourself. You are limited with the non-adjustable valvetrain that GM went to during these mid years. I would suggest the following:
Find a good set of OEM 049's or 781s complete for $700 to $900
Bolt on an AirGap intake $225
New Camshaft $350 to $450

This should get you 70 to 100 HP pretty easy and in that boat should push it pretty good.

Chris

Unitek

There is pic of the motor, can anyone tell me about it, like what generation or fuel injections on it ? also if i throw a bump stick in it will it mess with the ecm ? what about fuel and timing. it says set to 10*. I work on SBF race cars (mustangs) turning wrenches is my nature.

cstraub

It is a carbed (Weber) Gen 6.

Unitek

ok, so there is no sort of electronic control on it ? Is that setup junk or is it ok ?

Pat McPherson

I thought in 1998 the 310HP was a MPI engine, but maybe they made them both ways. The engine has L-29 100cc Vortec heads so don't advance the timing too far; stay under 30° total.
Good exhaust (Stainless Marine) really helped my 1999 7.4MPI. So that is a Great place to start. An Edelbrock RPM or RPM Airgap Intake would be a nice upgrade as well.
If you want to change the cam so she will make power past 4600rpm, you will also need a 454mag ignition module. Yours likely has a low 4650 rev limiter.
The L-29 heads stock have weak valve springs and can not take much more than .500 lift. I have a second set that were machined for new SS valves and springs for .600 lift. It cost me about $700...
If you want to tinker, be happy you have the carb version. I played with MPI calibration with a bigger cam and gain vary little with lots of $$ spent.
If I play more, the MPI is going in the scrap heep...

East Coast B

That is strange.... 98 with carb 7.4 which is 300hp at the prop.... mpi 7.4 is 310. Wonder if it's a genV motor. Thought 98 all the motors were mpi, nothing saying they didn't have some older motors sitting around when they put it together and I've seen models built a year or more before their actual haul/title date, maybe this is the case with this one.

Be careful how much power you put to those internals. Do some searching here and you'll find a LOT of info on that motor. Lot's of cast parts i.e. crank!!! The mag has the better internals. I had the 95 version of that boat with same motor, took a perfectly good motor apart and it couldn't handle the extra hp.

Good luck! It's a great boat!!!!

Unitek

Great, thanks for all the helpfull tips guys ! What does the MPI intake look like ? I figured it had weak internals thats why I figured on spending $1500 or so. This is what I figure im gonna do :

Intake
cam and lifters
air cleaner / flame arrestor
MSD Box

Possibly mild port work and springs or new heads (depending on $$$ )


Will the carb that comes on that motor be ok with the mild performance this boats gonna have ? If I do a MSD will it bypass the factory rev limiter ? Not that I plan on reving it hard but would like to maybe rev to 5000 max

Unitek

oh and some nice roller rockers and pushrods

cstraub

Unitek,
SAve the money on the MSD box, for this application the stock Merc unit does just fine. The Weber will work just fine. Intakes are where the problem is. . .my E-Brock book only goes to '03 and they do not list a dual plane intake for the "peanut" port heads. A standard RPM performer will be a hell of a mismatch when bolted on. This is why I suggested finding a set of 049's or 781's; large OEM oval ports. Match a cam to the heads and with the boat having low hours the OEM lifters will work for your build.