if you havent then defonatley check the deck, touurghley, i have found blocks that apear to be flat with the threads pulled up a little high. if it is only a small amount you can get away with countersinking the deck at the head studs. On later triumph engines it is not uncomen to take out the top few threads with drill. This results in the stresses beeing placed deeper into the block and helps you get a higher torque on the headstuds when trying to get engines to seal when running higher compresion ratioes.
You can allso work wonders with a good flat oil stone and a large glass of good scotch on decks that resemble the sea. though its obveousley best to get the deck skimed if needed.
Allso, are you re tourqueing the head studs a few times after instalation? dont go to far though as you can esaley overtourque a stud even with a wrench set at the desied value....
