88blackgt

i wouldnt say "unblowable," theres several guys local to me that have blown them on safe tunes, but they were running a ton of boost, usually imports or one was a gn(smaller motors that make all their power w/ boost). theres definetly better, but theyre a good choice.

r.barn

they're on my engine.

my engine builder couldnt say enough good things about them.

said on thier track car they would destroy head gaskets after
a few passes, but the cometics would last all season long.

pricey, but you get what you pay for.

BADNOTCH

I am o-ring grooving my block and heads. I was running mls fel pro. I have heard nothing but good things about cometic. I cant stand pulling apart a fresh motor because of a head gasket. If you arnt o-ringing your setup run cometic and you will be fine.

nmerrill

I blew a cometic head gasket.......on my yamaha banshee! I have heard good things about them. I have also heard you can re-use them

JD1969

While they are costly, there is a huge benifit in that you can re-use them a few times. Mine have been on and off two times so far.