Overheating nightmare - unsolvable please help

[svanhook5@comcast.net]

I have an sr20det(bb) engine in my 200sx se-r. After the

transplant my car ran great for about the first 4 months.

 Then one day we had a small se-r convention in Kansas

 City hosted by Brad Woodworth. That day we drove my

 car very hard for about an hour. It over heated pretty

badly that day(we did not notice until steam came out

of the hood)and has been doing so ever since. Now let me

 tell you what I have done to try and solve the problem.

The first thing I did was replace the radiator

cap(300zx 16lb) and the thermostat(170 degrees). Then

 I got a nismo radiator. That helped to control it a little

bit but it still over heats. After that I replaced the water

pump and while I was at it I put on the UR water pump

and crank pulleys. I have checked the radiator for

bubbles. The coolant has been replaced 3 times

and each time there is hardly a spec of dirt and no

oil in it. The exhaust is not steaming. the oil is perfect.

 I have done a compression check and every cylinder

 was within about 3 pounds( 155-158) of each other

( I replaced the head gasket and the rod bearings

before I installed the engine). The last thing that I have

 tried was to install flex a lite fans. Still no avail. I can

 think of nothing else. It seams to me that there is a

lot of heat between the fans and the turbo manifold.

In fact the new flex a lite fans are too hot to touch.

 Also, running the A/C seems to speed up the process.

 It will over heat in the city and on the freeway

(although usually in the city). Some times the car will

recover on its own. It will try to over heat but will

eventually go back down. Many times however I am

forced to shut off the car for fear of a warped head or

 blown head gasket.I really need some help from the

 list on this one. I have had many people look at it but

 know one knows what is wrong. I am tired of putting

in money to this problem and still not having it fixed.

I just wan't it to go away :)

Thanks to anyone who can help.

Shane Van Hook