Copper Head Gaskets


I've got a set of nice alum S2 heads, cut for o-rings (the block wasn't cut, just the heads). I've heard it's tough to seal the coppers for everyday use -- what's the cleanest way to handle this?

GE 1200 construction silicon or Dow Corning 732
Thanks, Jay

Incidentally, I've just heard (from Mickio, Performance Machine, Pomona, CA) that I could have the heads cut (further) for FelPro lockwire gaskets (.080 cut). My aim is a water & oil tight seal, rather than the ultimate in boost-holding.
The Dow stuff you can get at Home Depot. The GE stuff is a bit trickier. Poke around in the phone book under Silicones until you find someone who carries it. Usually contractor supply houses have it.