since the heads and intake have to come off, might as well get them port matched and hogged out. and since all that stuff will be off, you could sneak a CC306 cam in there
Imagine how that would sound through the cutout
Oh, and to answer the other part of your question. If the head gasket lets go completely, you might hydrolock the motor and bend/break your rods and crank, and that would F up the block. so you should get that fixed pronto!