^^ X2 ^^
if you just have the head off, i understand why you cut the o ring in the head. on the other hand, if your doing a complete rebuild, wouldnt it make more sense to o ring the block?
if you already have your block set up in the boring bar, it would be just one more minor step to cut the o ring in the block, then if you ever wanted to use a different head in the future there is no need to have it o ringed.
whats the benefit to a double o ring?[/QUOTE]
I'm not positive there is any. But when I blew my gasket, I was running 90psi+ and a single ring is no guarantee at that level. Some of the local pulling tractors are running 2 O-rings at some insane boost levels, so I thought that I would give it a shot.
Since then I've made some changes to get the boost down, so maybe it was overkill. I just know that I really don't want to pull the head again. One thing though, it took a while to get them seated. I torqued it 5 times before the nuts stopped moving.