Looks great, Steve! Let me know when you'll be at AMP and I'll try to drop in.
Steve, the car looks great! Ken Roberts posted this link in Johan’s SLC thread regarding PWM controlled alternators which may be your issue.
Conversions & Hybrids - 2 pin 2006 + alternator. Don't throw it away!! - I just swapped the regulator in my alternator from 4 pin to 2 pin, so now it's like a 2006 or newer alternator. Why??? Because GM thinks it's better than the older 4 pin one and they must know something. Oh but everyone...ls1tech.com