Thats the firing order for your car. You better find the correct specs on your motor like if its a mustang motor or not. Im betting you ****ed something up yesterday while timing it.
Either that or the guy i got it from took the distributor out and didnt put it back on the #1 cylinder. The wire that goes to the ignition coil has a lose clamp. Im gonna try to bend it in a little and see what happens. Ill keep ya posted.
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.
I'm usually not a forum Nazi, but we need to get real on the accuracy of tech advice around here. It's been a big faildozer lately.
The SPOUT connector is NOT a rubber hose, that would be for an old fashioned vacuum advance distributor. On EFI 5.0s, you have what is called a SPOUT connector. In layman's terms, a SPOUT connector is the electrical plug that inserts into the end of a wire cluster that comes off the distributor. SPOUT is short for SPark OUTput, and with it unplugged, the computer is unable to control initial ignition advance, and so you are able to play with it as you see fit. Once you lock in on the advance you want, you plug the SPOUT back in and drive.