ok so here we are 2020.. I have the chance to get either 9 thread stock heads or 4 thread pnp heads with new everything. I am doing a single turbo built 8,000 rpm Sullivan lower/hpp upper with custom cams... So the question is to go with the ported heads or stick with the 9 threads? need your guys input on this subject. I have read old post with back and forth reason too and reasons not to. I am at 300 to 400 price difference on the 2 so money is not a big concern.
