Is it necessary to use the Z1 steel gaskets when switching to hfc or are the ones that come with them sufficient? I've heard of issues with them blowing out.

 

they don't blow out they arr just too thin. I have mine double up with a generic gasket. So far no leaks. 1k miles.

 

Just for the record and for any people who search...

I installed my berk HFC about 3k miles ago with the gasket that comes with them. I sprayed copper spray on both sides and torqued like I would lug nuts. No leaks thus far.

 

Awesome. I'm at 3k miles with double gaskets also leak free.