I'd avoid 2 fans, they just fight .... I bet if you lower the water level in the rad to about half depth of the top tank [just always make sure the tops of the fins are covered an inch] your overflowing will stop - quite possibly the ticking too, although that's more likely normal exhaust component cooling, head pipes or such .... and if the rad is painted with a regular gloss black, strip it off and replace with a flat black rad paint .... for the long stops, shut it off!
Bill
