Reply to "Engine rebuild problems"

"Clouds of blue smoke" means oil is getting into the combustion chamber. There are two paths: from above via bad valve-guide seals or a plugged drainback hole so oil fills the rocker cover to the brim & runs down under the stock umbrella-seals. You seem to have taken care of intake mainfold gaskets, but this can be checked by pulling the plugs before the engine is warmed up; serious oil-burning will give an oil-wet plug in the bad cylinder(s). The other choive is bad rings that allow oil on the cylinder walls to creep past the oil control rings. Without being there, I can't diagnose further; I've seen brand-new std-bore pistons in 0.030-over bozes, mis-marked rings, etc, etc. Keith Black is a good brand, but like all cast pistons, they require a tight fit to the bore, while forged are tolerant of as much as 0.005" of slop.