Hey, they're bought and paid for. Can always swap to new heads later... life is too short to put stuff off sometimes, work with what you got for now, improve if possible later. What would it cost - the heads and a head gasket set...
What they said! Put it tighter and enjoy it for what it is now and upgrade later. I purchase my parts and simply store them for later. When I get everything I want the way I want it, I upgrade it all in one shot. BAM! Done.
It's worth the wait. And when you feel the power differance, it will be great.