The Twisted Wedge series, to my knowledge all come with 61cc chambers. Are you talking about a different TFS head? Hi-Port/TFS R series?
O-Ringed heads use Fel-Pro loc-wire head gaskets. The idea is to help make a better seal, better compression and it helps from blowing head gaskets with forced induction. The
"idea" is good but, I would rather blow a head gasket then destroy a piston. Not to mention the head gaskets are a fortune. They are about $100 for a set.
This is an O-Ringed Cylinder Head.
These are the Loc-Wire Head Gaskets....notice the metal ring around the cylinder, that fits into the machined groove on the head.