69 Chev stepside, 250. System not charging.

Alternator tested "passed" by Autozone. New regulator. Good ground. Battery test excellent (9 mos old). No fuses blowing, no spark at battery terminal when disconnect (ie no shorts).

Re-checked the wires, all show proper voltage/continuity. Still no charging.
battery static is 12.48v, when running 12.22v, when lights and heater fan on 12.03v revved to 2000-3000.

I'm beginning to think, although the alternator tested fine, that it must be the alternator. Any other thoughts??

Curious though, I can take short trips, 3 to 10 miles 10 times and the battery voltage never drops. If I go 100 miles, I run out of juice and it has to be jumped. And even though there wasn't enough juice to start the engine, once started it will go another 50 miles. (still won't start if you shut it off though) Wonder if this is significant?