best place to run the water dumps from i heard drilling a hole in the back of the intake and running from the back water jackets but what do you guys think i should take it from

I know of a guy who tapped into the rear intake jackets and dumped over from there with good results. Eleminated steam pockets and allowed him to dump water pressure. I think he played around with hose sizing to control amount of water.

I prefer the relief valve setup. Only dumps when it needs too, not all the time. Installed them on my stock 502's. Instant fix.

is there any other areas you can take the water from

I installed the Merc relief valves right before the t-stat housing and have the dumps going into the back side of the switching valves of my silent choice divertors to dump the excess water out my exhaust for a no holes drill thru hull install.

Others install valves on their sea strainers.

If you really have a need to dump from the rear of the intake that would be best but be careful about how much you are dumping. You probably don't need much from that location to eliminate steam and cool back cylinders better. You don't want too much so as to starve the front and exhaust of cooling water. I dump just past oil coolers and drop the water on the top cap of the Bravo. Reading 18psi measured at block drain there is an incredible amount of water hitting that top cap. It has to help cool it.

If your trying to reduce water pressure do it at the pickup. The little elbow hose between the intake manifold and water circulation pump allows the heads to be cooled properly if its plugged or missing, the back of the heads will overheat. Dumping water overboard from the back of the intake manifold, on a closed system(stock Mercury or Chevy) will cause uneven cooling, will have the same effect as removing the thermostat. The water won't have a chance to cool the engine evenly and there will be no warning on the temp gauge before engine is damaged. This usually happens sometime after the fact and engine failure will be blamed on something else. Reducing the flow at the pickup will leave the system working properly, if you reduce the water to much you will know immediately.

If you are having overheating problems more than likely something is wrong with the system, dumping more water overboard will make things worse.

I drilled & taped the back of my intake manifold and ran the lines to the front of the manifold.I have not ran the boat yet so i dont how it will work. I have heard that it is suposed to help cool the back of the engine.

When I went to crossovers I had a problem with not cooling the back cylinders #6 and #8. I kept seizing exhaust valves and hitting pistons. So I drilled out the back of my intakes 1/4NPT and used Posi Loc 3/8" hose. I then plumbed the water into the back of my SM exhaust manifolds. I will now always drill the back of my intake manifolds. 15-18psi water pressure.

My plan is to run a crossover pipe between the rear two ports on my intake and put a T-piece in the middle. I'll then run the T to a through transom fitting and use a plate in the fitting with a hole drilled in it as a tuneable restrictor. My plan is to test the size of hole required by drilling a small hole and opening it up more in increments until my water pressure is correct. Saves changing hoses all the time!

Not sure if it will work but there's one way to find out!

looks like im going to be pulling my intake to drill some holes today thanks for all the info