[Dave at Pelican Parts]

Have you looked through the timing article on this site? It has more detail than Haynes does.

The points-replacement gizmos will usually work better than points in a distributor with play in it, but they can only go so far. Some folks have had luck with rebuilt distributors from their FLAPS (Friendly Local Auto Parts Store). A-1 Cardone does them, but they seem to have something like a 50-50 success rate. Luckily, most of those places will let you trade in one that still has play in it.

27 degrees of dwell is not good. You're shooting for something near 50 degrees. The timing will be way off with the dwell that far out--remember, dwell changes have significant effects on the spark timing! And that could cause lots of driveability problems.

--DD