The water pump is a jegs long. Iím going to replace it with the kooler since I read those are really good. Got a new hose that dose the droop and I check the rad and all my fins are pushing out fluid, when I did the pour from the top hose.
That's good news and pretty much what I expected since your temps drop to normal after the initial run to 240 after start up.
I don't think you need a new pump if the impeller is not damaged and firmly attached to the shaft. But it won't hurt and will give you peace of mind with just a little lighter wallet. If you have to buy gaskets for the pump reassembly, you're part way there anyways.
My bet is still on the thermostat. Yeah, I know, 2 previously new ones.
When you install it, the pointy end points to the sky.
It wouldn't hurt to blow some water through the block while the pump is off. Just run the garden hose to the thermostat housing without the thermostat in place. Just to see if anymore gunk decides it wants to leave the block.
I'll be standing by to hear of your good results. There's a few other things that could cause this, but you pretty much ruled them out with the compression test that you did. Hopefully you'll be on the road and won't have to worry about any more issues from your cooling system.