electrical miss under load

I have a 350 with HEI distributor. When my RPM's get over 2000 the motor starts missing. I have changed the cap, rotor, plugs and wires. I can't check my timing cause all my plugs had to be rotated clockwise by one post for the car to run. I figure when the distributor was installed they turned it a little. So my 2 questions are

1. What is causing the miss? at higher RPM's it goes to machanical advance so maybe the weights and springs need to be replaced? If so would it be better to get a new distributor like MSD or Mallory.

2. Can I turn the distributor back or does that even matter?

Any and all help is greatly appreciated

The fact that the wires had to be walked around the cap doesn't mean a timing light won't work. The position of the distributor doesn't matter as long as there's enough range of movement to get the timing right.
Even though you have changed plugs, I'd bet you have a dead one under load. Buy one of those laser thermometer guns and check the temp of the plugs, chuck any that are colder than the rest.

Sounds to me you might just have too much timing. Retard the timing some and see if that miss goes away.