Lol jeese, when it comes to expensive computer stuff I make double-checking a mandatory activity; its nothing personal mate you know what a worrier I am!
the rear mounting cover for the motherboard will have a heater element which you connect to the mach II so for your mach I you need to cut it and stick it onto a molex plug in order to get it to work, or you can use a piece neophene pad instead of the heater.
Mate, Everything you need to mount the P4 is in the XP kit I have for the mach1, neoprene and all the gubbins. When I get the kit you'll have it. All you need is the Mach2 mounting kit for P4 and I have the rest.
