I have a 99 Jeep Cherokee xj limited, about a year ago my son and I went camping heading north over the grapevine it overheated. It also overheated heading south over the grapevine. I replaced the t-stat, water pump and the radiator ($100 spectrum). It ran fine after that, I went camping again but it overheated again. I bought the blown headgasket test kit and did the test multiple times and it passed everytime. Forgot to mention my heater core was leaking (a year ago) so I bypassed it. I do have a transmission and engine oil coolers mounted in front of rad. Should I get a better rad or mount a fan on it?, or...?