Where did u take the pressure from...Intake ???
That is too high..i would bring it down to 25 max..
But also i heard rev. a 598 over 5800-6000 is deadly !!

U may wanna run a little bigger prop on that engine to bring the RPM down and u should not lose any speed !!

Thanks I was just trying a 30 b1 think I will try a 32, with no sea strainer where should I install the relief valve ?

Just thought about this, u could also change the pulley on the raw water pump ?!

But i would install the relief valve after the pump !

It should be ...oilcooler > pump > engine ...

or is your oilcooler behind the pump ??

I used a block drain for the gauge, I have no oil cooler we run on pretty small lakes and oil temp has never been an issue. So I should install a t after the sea water pump with a relief valve to dump overboard, what size line ? I have one of those brass ones from teage

Size line ??? what ..on the relief valve..i would go #10 for the dump but u need to rig it in to the 1,1/4 water line that comes from the pump !!!!!

The oil cooler itself should help bring the press down a bit ..since u don't have one in there that may be the key !!!???

Also i take my water press from the top of the intake.

Fuel press...( N/A engine ) 7-9 PSI
Water press 17-25 PSI
Oil press 75-85 PSI
water temp WOT 140-165
oil temp WOT 190-225

Sorry thats what I meant was what size line for the dump. WILL The water pressure read less at the t stat housing?

It shouldn't but i honestly don't know...it may by a little !?

Thanks I will set it up and try it this weekend:

Cool, keep us in the loop if it worked !!!!

i had the same problem so we put a restrictor plate where the water thermostat goes with a smaller hole. it controled the h20 pressure but still had problems because the h20 pressure entering the boat was still to high as it kept blowing the hose off between the outdrive and the engine. to finally solve the problem we welded the water intake slit on the imco lower outdrive closed to about half the original size. my 2 cents.