you are saying you have good flow, and a good temp drop across the radiator but are still running warm
How are you measuring your temperature
IE: what type of gauge, mechanical ,electrical etc.
and
where are the sending units located. I do not trust gauges until I have verified their accuracy. I DO NOT TRUST GAUGES UNTIL I HAVE VERIFIED THEIR ACCURACY.
I use a digital thermocouple meter with probes that can be placed in multiple locations to do so
Once the probes are in place I will compare the gauge readings to the meter.
First test At IDLE. Write both the gauge and meter readings down from a cold start.
How long does it take to warm up and at what temps does the fan turn on.
Does the temp start dropping shortly after the fan turns on????
Second test: repeat the above tests while driving the vehicle short distances.
If the temp increases abnormally while driving it,
you either have to small or a blocked radiator, restriction in the system somewhere, (Do you have a spring inside the lower hose to keep it from collapsing IE: sucking shut as the rpms increase.)
lack of airflow to the radiator,
air going around rather than through the radiator or
worst case an overfilled block.
Do be aware that the thermostat also serves as a restrictor to keep the coolant in the radiator longer to exchange the heat and removing it can cause heating issues. One can substitute a large washer or gut the thermostat.
FYI I have seen more than one aftermarket gauge be off by as much as 60 degrees at 200. It seems as though the warmer the temp is the farther out of whack a bad gauge /sending unit will go.
keep us posted