Just did head gasket, water pump, thermostat, upper and lower hoses, and radiator. It does fine idling or driving on regular roads but as soon as I get into the hills it overheats. Also noticed exhaust manifold glowing red at about 3000rpm, figure these are two seperate problems. Any ideas?

It does have a 5" lift with 33" tires, not sure if that really matters.

 

This thread might be helpful....
https://www.cherokeeforum.com/f5/cat...low-red-73614/

 

Cat doesn't glow red, just the manifold. Engine runs fine and no dtc's.

 

It does talk about the mani in that thread. Your cat could be the reason its causing the mani to glow. If you noticed the first few post stated the cat is on a melt down clogging the system.... Check O2 sensors those also can be a reason.

 

Could the cat be clogged enough to cause the manifold to glow but not give me a drivability issue?

 

Well, my nephew had a issue like this, but it was a crossed plug wire lol, I dont think the cat has to be completely plugged, there is something restricting the air flow, I dont think changing water pump and thermostat is gonna cause that. I could be wrong tho... I am just a girl...