I don't know, it depends on the amount of cooling you'll need to get your 5 degrees. Anyway, I bet you could even use a computer liquid cooling system (the processors heatsink on the ignition module, the 120mm radiator in front of your car's radiator). I don't know if that would be enough cooling or how hard it would be to adapt the processor cooler to your ignition module, but always an idea for a small size. Mind you that the computer cooler will be twizce as expensive as picing up an automotive radiator at a junkyard. You can find radiators in junkyards of all different sizes, especially becasue a lot of bigger light duty trucks (Dodge Ram 2500 and F250s and up, and the like) have three or four radiators, one main for the engine, then others such as a transmission cooler, an oil pan cooler, or an additional radiator for the air conditioner. You'll just have to try some thigns and see what works best. (A junkyard will likely let you roll in and take various radiators and dink with them there to see if they will fit the way you want them to.)