Ironhead Was the battery tested and fully charged? I personally are not a fan of Optima batterys. Design is great for every where to mount it. Have had failures of them in higher vibration conditions. Lets test the battery with a full charge. If you have a head light and to wires, run the light of 60 seconds to take the top charge off the battery and test.
I can't under stand why they can't give you a full charging reading for the Alt. It could still be bad and breaking down once it warms up.
Wiring of the fans shoudl be in 12 gauge with heavy duty relays and using high speed only.
Is the heavy discharge happening at idle only? What is the idle on the motor?
If we raise it 100-200 rpms can the charging system handle the load? If yes, we may just need to get a smaller pulley on the Alt to increase thw speed of the Alt and keep everything charged. If not, and this was my car, I'm going to a 90+ amp Alt. Most cars and trucks on the street have over 100 amps now. The wiring is lighter in gauge because they removed the 10% fudge factor in safety of the trucks and cars. Saves money on copper which scraps for about $3.00 per pound.
Lets stay basic, check battery and test. After this we check rpm range with fans on and where the charging system can handle and charge all the normal loads on the system. Do this and come back with the answers and lets see wear this goes. My main concern is the AMP gauge, I have burnt off the insolators on this gauge with too much current going through it. I was running a 70A ALt with the orginal ALT from Ford. Over time the system could not handle the loads with being safe and almost cooked the dash and harness. You don't want to let the smoke out of any curcuit.
I will look at the March setup and see what the under and over drive ratios they have. I got a set of March pulleys for my FE motor and they where 20% underdrive and cause alot of problems.
Talk to you soon Rick L. Ps after we get this fixed we need to look at the curcuits for the fans and go to a larger wiring and 40 amp relays to protect the car over time.