The 302 GMC sat in the hot tank for a week at the machine shop, still was looking pretty cruddy inside when ya looked through the freeze plug holes.Not so much rust but heavy mineral deposits,specially in the bottom rear left side.The shop said it could be chemically cleaned by a local company, about 80 bucks.
Ain't got 80 bucks to spare on this project,man, this GMC stuff is pricey,the parts guys weak ski masks. .
Since I had to drill the block for a full flow filter before the pistons come, I dragged it home,down the steps into Tony's shop of horrors.
Took an old plumbers snake,the cheap 1/4 inch spiral flex type, cut off 16 inches.Chucked it in a drill, fed it into a hole,engaged the drill motor.Lots of dusty stuff flying out the holes,good. Then I bent a few kinks in the snake,better yet lots more dust, and louder noise,spanking that crap right out of there.
The shop vac blew out the dust,looks pretty good.Drag it back to the shop,into the tank again.
