piston rings

Washing the cylinders with soap and water in-car would not be wise IMO....; it'll get into the mains. Use ATF saoked into paper towels and go over and over each cylinder until no more grey color shows up on the paper towel. It usually takes 3-4 cleaningss with ATF to get it that clean; ATF will really suck the crud out of the grooves.

And, BTW, I have seen plenty of reference to Moly rings using a hone grit in the ranges of 300-400, especially for full moly top rings. But the Hastings/EngineTech moly top rings for the /6 are not full moly tops.

The one issue that really would give me pause for honing in-car is the grit getting all over the crank; the honing fluid will wash it down into the oil passages in the rod journals if you do not plug them and will also wash the grit into the edges of the mains. How well the oil pressure in the mains will push that out, I can't say. But then the grit will go into the pump. So that is is one good reason to not hone in-car. That all adds up to why I don't bother to do anythingbut pull the engine; you get aroudn all these issues. Easy to do since I have an engine hoist and stand!

So OP, are you just rolling your eyes by now? LOL