If you noted your deck height/head gasket thickness and a guestimate of your head CC's from what they're listed at in the charts you can figure your SCR then with your cam choice an estimate of the DCR & from that your octane needs. The period correct heads would not be unleaded compatible but depending on how hard your run it you can get by with unleaded for awhile but for how long I'm not sure. The open chambers/no quench is going to hurt (raise) the octane requirement EDIT If your close you can slow the timing somewhat to compensate but it will drastically hurt your performance