I'm wondering if your still using the old style fixed or a flex fan, they don't like to sit in traffic or run on trails. awesome for the strip though.

its hard to beat a clutch fan off of 78-87 gm diesels 5.7l olds or the 6.2l car or truck.  

I'm running clutch fan, the radiator is a aluminum one from BeCool.  

That's an excellent radiator. Is the radiator a direct fit for the CJ allowing you to use the CJ shroud? You'd mentioned moving the motor for better alignment.

The shroud must be tight to the radiator. If it is not, the fan will pull air from around the radiator and not through it.

The shroud is the magic that makes it all work.

It must allow the fan to create a suction through the radiator only. Air will follow the path of least resistance, and there is a fair amount of resistance through the radiator.

What diameter clutch fan are you using?

I have had poor results using a 16" fan, fair results with a 17", and outstanding results with a 19" OEM clutch fan on some V8 S10 conversions. All using the same radiators with different shrouds sized for the fan diameter.  

ftgiles:
That's an excellent radiator. Is the radiator a direct fit for the CJ allowing you to use the CJ shroud? You'd mentioned moving the motor for better alignment.

The shroud must be tight to the radiator. If it is not, the fan will pull air from around the radiator and not through it.

The shroud is the magic that makes it all work.

It must allow the fan to create a suction through the radiator only. Air will follow the path of least resistance, and there is a fair amount of resistance through the radiator.

What diameter clutch fan are you using?

I have had poor results using a 16" fan, fair results with a 17", and outstanding results with a 19" OEM clutch fan on some V8 S10 conversions. All using the same radiators with different shrouds sized for the fan diameter.

Yeh it's a direct bolt in, I got the radiator from 4Wheeldrive Hardware. I have a 17" cluth fan. The shroud is a from a CJ, it had to be modified a little to work with radiator. It doesn't suck air from around the radiator,and there is about 1" clearance from tip of blades to the shroud. What do you think, step up to a 19"?  

As close as the 17" fan is to working, the 19" will solve it for sure. You will see a 25 degree difference at idle.

Can your existing shroud be trimmed to fit a larger fan and still follow the "propper" shroud clearances as stated earlier in these posts?

How many blades on your 17" fan? If not 8, then even an 8 blade 17" fan could be all you need.

When you shut down the motor when it's hot, does the fan stop rotating instantly? If not the clutch is worn out.

You'll have to do a little research for 19" fan selection, but they are cheap from the Chevy dealer. Start your research with late '70s to mid '80s GM full size trucks.  

Are you using the V8 shroud for a CJ? The I6 shroud is for a smaller fan. I think the stock 304 V8 CJ used an 18" fan.  

Have you tried the 30 minute hood open test? This is also important. If the temp goes down you can start looking at things to expell heat out of the engine compartment.

The biggest culprit of excessive heat is headers. Header wraps and coatings can help as do properly located hood vents.

Another thing you can do is turn the temp and heater fan on high to see how a little extra airflow (through the heater core) will affect engine cooling.  

There is enough room for the 19", the shroud can be trimed and still work. The shroud came from a Jeep with that had a 360 in it. I just installed a set of Headman headers(coated) on the Jeep about 6 months ago. It doesn't have a heater or A/C. With hood open it goes down a little, about 5 degrees on the gauge.  

Ya. Head out to the auto recycler, or junk yard if you're a mean nasty Republican (this is the political season right?) and get a standard rotation fan out of a pre '86 truck (no surpentine belt).

All the V8 trucks I think had a 19" fan. The biggest difference between them all is in the clutch (heavy duty cooling).

If your not into the junk yard sceene, the 5700 series Flex-A-Lite fans are an oem type fan. The 5719 measures 19.25" in diameter and 2 3/16" width. Click here for more info.  

Thanks for the info,I'm going to see if the 19" will solve the problem. I checked the clutch, it's working properly. It's probably like you guys are saying it just needs more air flow.