Head gasket troubles.
First , if the cylinder head or the block a has ben seriously planed it is wise to run washers under the head bolts. This pevents the possibility of a bolt bottoming out which can happen without out you realizing it.
Secondly alway torque the head in steps. We start at 50 and work in three steps to the final value. it is amazing how much they will creep. As a rofessional i cannot trust the customer to recheck so we do it this way every single time to eliminate problems. Also another problem I often see is runnig lower octane gas that the engine requires. That will kill a hed sket in no time under full power. Just a few tips from an old guy that may help.
