53 chevy on 95 s10 frame cooling issues

[altereddezignz]

Hello everyone. So we finished up our project and have had some cooling issues. Here is where i am at and what the issues are.
53 chevy 5 window
95 s10 frame
Radiator link is below.
165 Degree thermostat
15" electric fan on engine side
vintage heat and air so truck has an ac condenser
Texas speed small cam
small stall
stock motor other than cam and stock trans other than convertor
Trans cooler with electric fan mounted to the frame.
Shorty block hugger headers
2.75 exhaust.

Issues when we changed setting in shop truck will heat to 185 and kick fan on then cool to 175 and shut fan off. This is how the computer is set up. Drove truck to at 60 degrees outside and truck got to 200 setting at stop light with fan running then will cool off some when driving. It was back at 174 when we got back to the shop. Not sure what the issues are. Almost 1000% sure there is not an air pocket. ECU coolant temp says about 6 degrees off what the gauge says. Fan kicks on at 185 off at 175. Does have antifreeze in it. We filled the radiator with the heater core valve open and heat does blow very hot inside so we know there is water moving. You can remove cap and water is rushing by in the radiator. Truck runs great other than this issue..

Any ideas.. Thanks. Oh with the factory 195 thermostat truck would hit obove 225. We moved the radiator back and ac condincer forward and let us put the fan between the motor and radiator. At that same time we also changed to the 165 thermostat.
Truck does not miss, runs good, no water in oil and no moisture in exhaust. No loosing water, no leaks, Good compression. So im at a loss..

http://www.northernfactory.com/HIGH_...DIATORS/205156