I just wanted to write a big Thank You to all the guys on this forum.
I had just flushed the cooling system and on a little trip to put gas in the boat one of the straps on the stock radiator broke and the fan blade spun it right into the radiator and punctured it.
Sooooo, I get a new radiator and while I'm in there I replace the belt, upper and lower hoses, thermostat and the e-fan temperature sensor. Now it's running hot over 210 -- I know that that is the normal temp for a 4.0L but my jeep has never run that hot.
So I spent days reading on this forum, I was considering everything from a new radiator to an e-fan switch and this http://www.angelfire.com/my/fan/CTS.html .
I got up this morning and decided to go simple, I got a new mechanical fan clutch and drilled the little hole in the top of the thermostat and this time I mixed the coolant before I put it in and let it bubble out for a long time on the incline in my driveway. I had thought I was going to be smart and use a little math to figure out how much to put in but that was a stupid mistake -- mix it first. Now it's running right between the quarter mark and 210 and I'm ready to go fishing again.
Lesson Learned -- go simple first then get into all the complicated stuff..
Thanks Guys!!!

 

Good to hear you got it taken care of. And you saying to start simple is some very good advise.

 

No doubt, some dudes just replace the cylinder head.