The best thing you can do for the XJ in a high temperature environment is vent the engine compartment as much as possible to increase airflow around the engine. Hood louvers work well, but tend to allow rainwater in. Removing the hood air seal on the cowl and raising the hood 1/2" in the rear also helps. The problem is that air gets into the HVAC intake. My thought would be a pair of small hood scoops installed backwards.

 

Luke - no need to get the upgraded radiator. I'm down in Tucson, AZ and got the NAPA one. It worked great and never got over 210 degrees when I was done - that included idling in the summer with the A/C on.

Here's my writeup on my build thread below:

https://www.cherokeeforum.com/f46/19...246709/index2/

 

I've done the conversion and I have stress tested the vehicle way beyond the average trips to the grocery store. We drove over 19,000 miles from California to Canada to Maine to The Florida Keys, and back to California again. I have driven it through the Mojave desert doing 90 MPH during a heat wave and I've crawled up the steep mountains of British Columbia in the summer doing 25 mph (Their speed limit, not mine). Our XJ is our daily driver and we go all over Southern California in all types of weather on the regular. Here's what I can tell you:

1) We have the Spectra radiator which I am pretty sure is identical to the NAPA one. It has worked flawlessly, you don't need to overspend. It is fantastic and still going strong, but if you already got another one by all means use it.
2) The bleepin Jeep video is excellent with one exception: He recommends using plastic connectors to go from 3/8" to 5/8" hose for the heater core. DO NOT USE THESE. JUST PUT THE HOSES DIRECTLY TO THE CONNECTIONS THAT THEY FIT. In the words of Cruiser 54 "The heater core doesn't care which direction the coolant flows", and he is absolutely correct. Why shouldn't you use these? After doing 90 MPH during A HEAT WAVE IN THE MOJAVE DESERT for a solid few hundred miles we had a catastrophic failure when beginning our ascent into the San Bernardino Mountains. One of those adapters broke from all the heat stress and we lost all of our coolant. Thank goodness for AAA! Also I do not use the plastic heater control valve for the same reason (one less thing to potentially fail) , so coolant is constantly flowing through my heater core.
3) Put a protective heat sleeve on your lower radiator hose. Mine rests on the oil cooler line and has begun to leak over time. I will be replacing it soon and making sure I use a sleeve this time.
4) The only other issue I ever have with the system has been the coolant overflow bottle. I've had to replace that twice, which is partially on account of my own setup. Just another little thing I have to address at some point but not really an issue whatsoever. I use a cheap 8 dollar one from NAPA.

Hope this helps!

 

Thanks for the advice, I already purchased it on black Friday. It was about 100 doll. Less.but I'm planning on towing a 16ft trailer behind it besides being a daily driver. Also the Mishimoto radiator is lifetime warrantied so hopefully that will make me feel a little better. I actually think there is a fairly new radiator in my Jeep now if anyone needs one that u know. I also picked up vintage Jerry can brackets that is hard to find. I purchased mine new online, then a month later I found two at a garage sale. Lol always happens that way.