All good suggestions here and you have done very through homework.
First, buy some instrumentation.
I paid $27 for my IR thermometer, HF on sale.
Many multimeters have a temperature function using a Type K thermocouple. You can find thermocouple wire at industrial salvage. With an oxy-acetylene torch you can make your own thermocouple junctions.
All total, this should be less than $100 and can be useful for a lifetime.
This will let you see what the actual temperatures are under a variety of conditions.
First will be to calibrate your gauge. Find a large electrical O-terminal. You want one that will fit under the temperature sending unit and fits a small wire, say 22 Ga. (1 mm). Get a terminal about the same thickness as the aluminum sealing washer. Leave the sealing washer out as soft copper terminals will seal just fine.
Once you make a thermocouple junction, simply crimp it in the terminal. Run the thermocouple wire into the cockpit. This will let you measure the actual temperature and the ‘Porsche’ temperature at the same place and under the same conditions. Simply make a measurement at every mark on your Porsche gauge. As a fancy alternative, print a little label to stick on the gauge glass.
Is the engine actually running too hot?
A good clue as to the proper cooling is to compare the thermocouple at the sender (the coolest oil in the engine) to the oil in the pipe coming out of the engine.
At the pipe, use another thermocouple on the pipe. Use a hose clamp and a little piece of a rattle-can cap between the clamp and the thermocouple (this prevents the clamp from cooling the thermocouple). Again run the thermocouple wire into the cockpit.
During engine warm-up, you will find the pipe temp & gauge temp will track each other, pipe hotter. As the thermostat opens (starting about 180F), the pipe temp and gauge temp will diverge. Above where the thermostat is full open (about 210F), the two temperatures will tend to converge )mostly by the gauge temp rising).
Lots of data points are necessary so get a passenger.
Repeat the process many times.
The IR thermometer is a great tool for measuring exhaust temperatures at the 3-into-1 junctions to spot L-R differences. With heat exchangers it is a bit more difficult to measure individual exhaust. Hard-wired thermocouples are better.
When measuring cylinder head temperatures with the IR thermometer, choose a location and position where all six measurements are taken the same – well, as much as possible. Thermocouples mounted in the heads are better.
Knowing the temperatures will help with the MFI.
Assuming everything is as it should be, how do you make it cooler?
Easiest is with the engine cooling fan ratio. Your ’72 911T fan turns 1.3:1 of the crankshaft speed. At 4500 rpm, the fan is turning about 5850 rpm.
There is a crankshaft pulley and fan (or just hub) that changes the ratio to 1.82:1 with standard used Porsche parts. At 4500 rpm, the fan now turns about 8190 rpm. That is a 40% increase in cooling. There is marginal increase in power to drive the fan faster; not noticeable. A good (undamaged) fan can turn above 15,000 rpm safely.
A second, easy fix for track use is the ‘Rubbermaid Solution’.
http://forums.pelicanparts.com/porsche-911-technical-forum/150982-water-vapor-cooled-911-rubbermaid-solution.html
Every 911 benefits from having a front mounted oil cooler.
There is a great deal on Pelican about this.
Best,
Grady.