My 383 SBM has o-ringed heads and block. It's a 13 1/2 to 1 alky dirt track engine.

I don't know what kind of gaskets it had when it was fresh in '93 but it has Fel-Pro's installed during the last time it was opened up in 2007... still used the o-rings and the original builder did the refresh.

Now it's getting redone again and I would imagine I'll use the newer MLS gaskets... Fel-Pro or maybe a Cometic brand. Hell I might go back to a steel shim gasket... who knows. I'll be talking to the engine shop this week.

RR... with a 9-1 I would thing the coppers would do just fine.