I am going to be running -2.2cc flat top pistons (stock bore engine), and I need to know which head I should run. I have some stock 853's and the stock 862's. I plan on running nitrous, and eventually about 7-10psi from a Procharger. Would it be more beneficial to run the 862's with the nitrous, then put the 853's on, or could the 862's perform well with the mild 7-10psi?