I put a bar into the intake port, but I can't break head loose. is there something else I can do ? 71 240z thanks, timsz

If you scroll to the bottom of this page you will see a thread by Galaxybj who used nylon rope stuffed into #1 & #6 spark plug holes to help lift the head off when the crank was turned.

Make sure you took out the two little bolts in the front of the head!

Every time that I have had trouble removing a cylinder head from an engine it turned out that I had missed a head bolt somewhere.

(Sometimes that is easy to do if the engine was dirty.)

When the 14 head bolts and 2 front cover bolts are removed, a rubber mallet gives enough persuasion in my experience.