[nkaminar]

Even a new head can be slightly warped. There can also be some piston interference. Put some Plastigauge down on the block in several places and then bolt the head down without the gasket. You do not have to apply full torque but just enough to be sure the head is down. There should be no more than 0.002 gap anywhere. Do not turn the engine over when you do this and rotate the engine so that no pistons are at the top before doing this test.

Then place the head on the block without a gasket and without fastening it down but resting on the block. Turn the engine over by hand and note if the head rises. If it does you will have to have the pockets in the head machined. Some people have used two gaskets but I do not recommend that. You can do this test first.

I have had the best luck with the Best brand gasket and the copper spray gasket sealer. Other people have used that same gasket without the sealer and report good results. With the new head and surfaced block you may be able to get by without the sealer.