[Goose]

Brent,
I just thought I'd chime in to let you know that, as others have previously stated, Don Gould is the right guy for the task.

I had a 750 Speed Demon on my 351W that was causing all sorts of problems. With Don's guidance, I now have a 650 Speed Demon and a recurved distributor (initial advance 20deg, 34deg total) that produces a very snappy throttle response, idles great within a few seconds and, with some idle mixture adjustments, is producing clean spark plugs (vs. the previous, black, sooty ones).

Given that your initial advance is only at 12deg, I would suspect that that is part of your problem, but every motor is different. Don had me advance my distributor 2deg at a time, with a warmed up engine, turn off the engine, let it sit a few minutes and try to refire without touching anything. I continued doing this until the engine did not want to fire easily and began to idle rough. At that point, I backed off 2deg to determine my initial advance but could not run it there until the distributor was recurved for the appropriate total advance. Confirm the process with Don; he's a great guy with a lot of advice to give.

Gus