I shot myself in the foot. Well, not literally, but originally I decided to do all the grunt work and then just have a licensed electrician come in to spot my work and do the final main panel hookup before the rough inspection. Not real keen on doing the live electrical work personally. But, seems with the price of gas these days, no electrican cares to come out for such a small job within less than 3 weeks, or for a reasonable $$. So I shut off the Main, opened the panel, checked for hot and test fit the 100a breaker. Since I already had the right breaker, I figured I'd give it a go...