cooling problem from hell, part duex!

[fiveohpatrol]

ok, for the ones that didnt read my last post, i put an explorer intake on and something in the install went bad, fixed the leaks and it was still overheating, put a new rad cap and thermostat in last weekend and well i thought it was fixed, it stayed a little under 180 last sunday, then i had to go back to school and got back this friday, drove it that night and it was fine, even did a few sprints to 125 or so and it only went a little over 180 for a min and then went right back down after i beat on it, drove it saturday morning and it was fine as well, sat night was a different story, it never overheated last night but it did get to and stayed at 190-200, then today i drove it and it went to about the same (190-200) and was pouring a little out the resevoir neck, came home looked it over and the radiator was just barely warm as well as the upper hose, drove it again and the temp went almost all the way up to about 240 or so no good, came back and same thing, the radiator was barely warm, but then after i let it sit for a minute, the radiator and the upper hose got hot, but they werent when it was running, could this be hot coolant from the engine going back into the radiator through the lower hose? did i buy a bad thermostat, i got an 180 degree made by Stant, this is the worst experience i've ever gone through with any car, i need an expert to look at it

------------------
88 Notchback 5.0, 3.73's, Explorer intake, pulleys, Crane 1.7's, BBK headers, off-road H-pipe, flowmasters, subframe connectors, 65mm TB, shift kit, March ram air kit, motorsport wires, MSD coil, upper and lower control arms, 155lph fuel pump, cheap 2800 stall, Crane Adj.FPR, best time- 13.99@99.75, not yet tested times after rocker and intake install