While that was drying, I went to work on the rusty, greasy, cruddy manifold. I wish I had gotten a good "before" pic, because it wasn't pretty.
I went at it with the angle grinder and the twisted strand wire wheel, which made huge strides.
I then installed the little drain plug and filled the water jacket with muriatic acid.
A leetle bubblin' going on:
About 15-20 minutes later:
I flushed out some flakes of rust and chunks and some crud. Seems pretty clean inside now.
Then a final once-over with a wire wheel and a wipe-down with solvent to prep for priming left it nice and clean:
