The Stovebolt Site Forums The Shop Area Engine Shop timing issues

I'm having problems getting the timing even close to being right on my '70 C10. It has a 350 in it and I have set the points dwell to right at 29-30 but can't get the timing marks to line up. By that I mean the harmonic balancer timing mark is way off by as much as 2 inches to the left of the timing indicator plate. The distributor needs to turn clockwise more but it is to the point where I can't move it anymore. The engine will start but is very rough. If I set the dwell higher at say around 40 the engine runs smoother and the timing marks are closer to lining up but still off by about 5 or 6 degrees. Is this an indication that the distributor needs to be rebuilt/replaced. It is the original and I guess I should have changed it when I put in the remaned engine back in '02.