in-line 6 overheating problem

[moneyhole]

Thanks for replying to my post so quickly. It has not been run but 3 hrs since 2008 - after the gentleman changed out the engine, prior to me buying it. I will click a picture of the 3" heat exchanger and coolant system tomorrow and see if I can learn how to post pics on this site. Like I said, with 60 psi on the muffs and opening the manifold and h. exchanger port and no water coming out at all, I suspected the stern raw water pump. Who is the best place to deal with on Mercruiser parts? I'm in Va - near Richmond. Thanks