The 3" replaced a 3" so I can't say for sure. The 3" HX is held on to a bracket with large hose clamps on my engine. If its the same for yours, then just get larger clamps and some rubber material like an inner tube to use as padding between the HX and the bracket/clamps. If the hoses are painted gold like the one in your pic well those are likely original and way overdue for replacement anyway. I measured the old HX in the garage and its 13.5" long so maybe they went to a 3" HX to make it a shorter package? I would measure the hose nipples on the 2" HX and confirm that the 3" HX is compatible. Lenco should be able to answer that question for you. I wouldn't touch the pump unless its giving you trouble! Fix one thing before messing with another, or you might end up with new symptoms and not know what caused it. Some new hoses, a new HX and you will be adding enough coolant to make this a bonafide coolant change, and you should be good to go. RT