Right now i don't have any class rules I need to follow as I'm using the car for open track days. Just looking for the most economical/practical method to increase HP. However, I will be looking into time trial/racing classes before i make any mods. I would love to eventually do wheel to wheel racing but it will more than likely be cost/wife prohibitive so right now I'm thinking mods are wide open.
The main reason I was looking into swapping heads is that it seems there are more options for the focus as far as cams, valves, ect. on the focus head than the ZX2 head?