Aluminum head question...

Fel-Pro's or similar would be my preference. I think if you go copper you need to have the block o-ringed (wire type) to create a compression seal and copper is sometimes harder to seal fluids with. If you go copper I would consider using the Flatout rubber coated copper ones as they are desigend to seal better.

I used a combo of the RCC copper and the Felpro racing for my current smallblock with eddies (ended up with closed chamber heads and domed pistons so this created the quench clearance I needed). The Felpro's have the wire ring for sealing so I didn't have to o-ring. I have only put about 50 miles on the combo but they seem to be holding well and have no leaks.