I have been searching but cant find anything about this. Most of the head bolt holes in the block go completely through to the water jacket. If you chase the bolt holes how do you keep junk from falling down into the water jacket?

 

i just got done doing this about 3 hrs ago. and basically....you dont. most of the junk sticks to the thread chaser on the inside grooves. the rest (very minimal from what i saw) falls into the water holes. not that it was that clean to begin with. there was already some sediment in there that i cant get out anyways. and my block was dipped. hope this helps. oh, and have fun!

 

If it's down to a bare block, just flush the coolant system with a water hose

-Shannon