motorcraft is form oem stuff anyway, ford dont actually make the ignition amps, they are (initally masde my magnetti-marelli, but now there are several other companies who make the same unit as its fitted in various other cars aswell.

like above, try the cheap things first, a set of 071 (im running these with no misfires at all) and for the price of them, they will far outlast the champs and give better idle running.