If your doing a swap soon dont waste your money on a clutch, ride it until it blows. if it blows by the cheapest clucth from a local autoparts store or from someone here, most likily it will get you from A-B till your ready for the swap.
Good radiator, fans, ducting. most rotory tuners I know run alittle extra fuel. this is for 240's but it goes the same with any cooling system http://home.satx.rr.com/nissanweb/RadTest/RadTest.htm
if its a re-tuned ecu most likely you wont be able to read codes cuz that is removed the light and all that stuff, this is how it is on my rs enthalpy ecu. check for vaccum leaks make sure the vaccum hose is connected to the fuel pressure regulater, is the maf wired right or is it good at all...
haven't some people here been to his house and maybe, posibly know his address, where this small misunderstanding could be resolved like civilized people would do.:D