Looks like I have the charging issue under control- I pulled the alt cover & cleaned the feed wire eyelet & applied a little low temp electric grease to the terminals. Now the voltage doesn't drop appreciably (or the idle) when the lights or cooling fan are on.
Got the 85 Mazda RX7 AFM set up (7 clicks loose, f/p cutoff pin moved) to give AFR's in the high 11's low 12's * WOT, feels very nice.
Another issue I've noticed since I added the heated O2 sensor is that it's too lean during warmup - no problem if you're moving, but at idle it was kinda lean.
So, I installed an ECT from a LH2.4 Volvo system ( 0280130032 ) 1346030, which operates over a similar range, but doesn't drop resistance so fast in the warm up range. The stock ECT is under 500ohms by 150ºF. This one doesn't go under 440ohms * 190ºF (stock drops to 200ohms * 190ºF), so it's keeping the system a tad richer.
EDIT: hmm.. just checked the graph for this sensor,
EDIT: stock ECT graph (026) same values indicated as the 032 (?)
and my findings are not in keeping with it. Either the engine is colder than the gauge indicates (ran til cooling fan cycled, checked resistance value of sensor = 440ohms), or my test was erroneous. However, it is still higher resistance when checked against the stocker at similar temps.
Now the AFR's drop into the 13's under mid throttle, instead of staying in the mid to low 14's, definitely feels better, and still idles in the 14-14.7 range.