I want to know if i can run with crossover and thermostat without bypass if i drill a hole in the thermostat?
I want to run the egine at 150F in a 65-70F water temp. Is that this hole will drop too much my engine temp?

Any help will be appreciated.

Aren't you installing a supercharger? Any reason why you want to run the engine at 150* and run a thermostat?

You cannot run a thermostat without a bypass. When the thermostat is closed, how is your exhaust gonna get water? Drilling a hole isnt enough. Not too mention the water PSI issues you'd be having.

Yes i have just install a (B&M 250) on a merc 525sc with CMI headers. For the th setup what do you recommend? I know i need a good oil temp i dont have oil temp gauge for noe but the engine is setup with the stock merc oil thermostat.
For the water temp i dont want to run it to low and making condensation. Do you run without th and still have a good water temp?

I've never ran water stats. Just oil stats. Water temps around 100-110* on my stuff. Cold water temps helps ward off detonation.

You have never get engine problem at that water temp?

What is your temp at idle?

I will probably try to run without stats this summer, Do you put water restrictor to help to control temp?
I know that he have several people run her engine like that, but does the engine need more piston to cylinder wall clearance due to less expansion of the cylinder block?

I would be most concerned about water pressure. I had to put pressure relief valves, and water dumps on both engines. I was seeing pressure around 40-50.