Did you seal the intake ports of those steel shim gaskets with something? I allways use the stuff from Loctite that comes in a can with a brush. Blueish/purple looking stuff. I forget the name of it.
I did a cam change about a year ago and used the above steel gaskets and had no trouble with them. But this time knowing that the heads and intake have had work done to them I was :scratch: about the steel gaskets this time.