whats the difference? what do you reccomend?

 

o-rings a lot less problem

 

Not sure of the difference, but I run o-rings in my 94 cobra with twin turbos. I machined it myself and put the rings right where the fire ring is. When I torque the heads down the o-rings crush right up into the fire ring. Never blown one since. I made the rings from stainless wire and used the Iskenderian racing cams groove-o-matic tool to make the ring grooves in the block head.

A lot of guys say it is old school, but all I can say is that it works and works VERY well (at least on mustangs)

 

the difference is fire rings is a .105 wire which goes .015 thousands in the head and 0.15 in the block with .120 thousands wide grooves, the gasket needs to be modified to use fire rings, o-rings is a 0.41 wire that you machine into your head with a 0.39 groove and you leave about .010 - .012 postrution using a stock gasket, what o-rings do is help the stock gasket fire rings holding that extra pressure down..its what i would recommend