halffast,because your boat is a light cat with a na engine and a aluminum block i think you would be ok at 130 to 150 deg water temp.

Dont know if you are talking about the water transfer from back to front by the intake? I will try to put some pic tonight on my water transfer setup.

Super, basically I am talking about the water lines going from front water ports to back on an intake manifold, as discussed in this thread:

http://www.offshoreonly.com/forums/g...-manifold.html

The Dart intake I plan to run does not have any bosses or ports on the rear. This may or may not be the same is what you guys are discussing on a manifold for a supercharger.

Thanks.

Arizona Speed and Marine has a 120 deg. thermostat for use in supercharged engines. I use them along with Stainless Marine crossovers with bypasses. I also ran hoses from the rear water ports to the front and put (2) 1/8 holes in the edges of the thermostats. My temps are rock solid, don't vary more than 2 or 3 degrees.

No ones said it so I will, there is a SPECIFIC reason why Procharger wants you to run a crosssover and keep the motor as cool as possible, this allows you to run the most boost with the least amount of octane and the most timing. When you lower the operating temp and increase the fuel you will be able to make the most hp. My 540 runs 100-120 degrees and I run 12-13 psi of boost on 93 octane, if temp was closer to 160-180 that would cut my max boost back closer to 9-10 psi and also my timing under boost. Timing under boost-on a 800-1000 hp innercooled blower motor you see gains of 20-40 hp most of the time for every 2 dgrees more timing you run untill you get too close to max and egts or knock goes crazy. The 2 draw backs to running this cold is increased cylinder wall wear and sometimes efi driveability problems IF ecu isn't re-programmed to get out of cold start warm up enrichment mode at the normal operating temp . Years ago I read where Ford engineers documented advanced cylinder wear from running motors too cold which resulted in ring seal loss and quick forming of taper and a ridge on top of the cylinder. In my own experience however after 100-200 hours of running at 100-120 I found no ridge in my blosk and virtually no taper so maybe having fuel injection and less cylinder wash makes a difference in todays world and we are not talking 100,000 miles bewteen rebuilds here either.
As far as running a naturally aspirated motor at 100-120 it too is going to allow you to run a little more compression and give it a little more fuel which should make a small gain in hp, I would shoot for 120 or so though. If a motor was bone stock and already happy on low octane I wouldn't waste my time but if your trying to run a motor on the edge (max compression on pump gas) I believe a crossover and lower temp would be a good thing as long as the oil is still getting up to full temp, Smitty