Yikes, this thread is off to a bad start.
You set timing BEFORE TDC. The reason you set timing advance is so the flame front has a chance to expand before the piston reaches the top of its stroke (TDC). If you accidentally set timing after TDC, you'd know it, because the car would run like crap and the headers would probably glow red.
For the love of God, please put the spark plug wires back where they are supposed to be for the HO firing order. Playing around like that risks blowing up your engine.
Also, make sure you're setting your timing with the SPOUT connector unplugged, and then don't forget to put it back in when you're done.
IIRC, I believe rotating it clockwise advances it, but once you get in there and twist it, you'll be able to see with the timing light whether you're advancing or retarding it.