What doe it do, and do I need it? I'm doing my vacuum deletes.

so i want to go to the s13 sr20det 3 row radiator this summer as the current one is bad but i was confused with the whole conversation in other threads on the thermo switch. I know on the stock radiator the switch is on the bottom of the radiator and with the new one they obviously do not have those plugs. Do i need those for switching to the new style? For the fans i was thinking of just running a toggle switch with direct on/off power. If you guys could tell me a little about the thermo switch

#1 diff,,,200.00 #2 diff,,,200.00 #3 diff,,,125.00 needs bearing #4 diff,,,200.00   6 bolt cv axle shafts 75.00 each. Boots are stiff but no gaping cracks.   have a couple parts axles,, basically needs boots/rebuilt.   http://i179.photobucket.com/albums/w316/conquest232/Mobile%20Uploads/20150507_142247.jpg http://i179.photobucket.com/albums/w316/conquest232/Mobile%20Uploads/20150507_142303.jpg

went to a scrap yard and weighed my 83. with me in it, 1/4 tank of gas, and a tool box it weighed in at 2840. mind you it has a full 86 interior, five lug swap, 88 rear end, and rear 8s all around. little booger is fast to