My buddies new 454 build milkshaked , whats the best way to clean out engine
also he has the same cam as before so what should we look for as to cause? He had about two hours of break in time .

exhaust leak will cause it to suck water back up.but it could also be intake gaskets,head gaskets,cracked head.............
clean up,,brake cleaner and a vacuum after intake is off.diesel fuel and a road trip down a bumpy road for the stuff in the pan.left overs get taken care of when the engine gets hot and it burns the water out.use good synthetic as the oil ,you'll need all the protection you can get.

Ok I'll let him know thanks

I just went through this exact same thing. Ended up being the intake gaskets. What I did was removed the intake and cleaned up as much as I could with paper towels. Then put intake back on and filled it with cheap oil. Fired it up and let it run for a little while on the hose then shut it off and drained the oil. Then refilled with good oil and I was good to go. Have about 15 hours on motor now with no milkshake. Word of advise is to check the torque on the manifold several times. I had to go around my manifold 6 times before the gasket stopped compressing. Also make sure the tabs that hold the lifter valley pan are not interfering with the intake gaskets. Mine were on the new gaskets so I trimmed them a little so that they cleared.

Good information, I sent him a link to thread.