This time I used a sheet of glass with abrasive paper on it, then rubbed both the head & barrels down to make sure they were perfectly flat, coated both sides of the head gasket with "h***a bond"torqued it down then ran the engine up to temperature a couple of times then "re-torqued the head after it had cooled (it did tighten a bit more) up till now iv'e not had any more problems 
