Wow, quite a variety of answers. Since I am fundamentally a lazy person, and the distributor is already in (and it was hard to squeeze it in there, as far as I can tell the O-ring was a bit thicker than the old one), I may just try leaving the spark plug wires about where they were and see if it can be timed to run good, and it that doesn't work, shifting the wires one position clockwise to match the rotor.

Here's another potential problem, though: the engine is a 440, and since it's a late 70's New Yorker with all the options, it's really crowded around the distributor. The Procomp distributor has an integral ignition module that sticks out of the side, and it limits how much you can rotate the distributor. Here's a picture:



The shiny rectangular lump at the upper left with the two philips screws is the ignition module, and you can see with a small counterclockwise turn it would hit the corner of the intake manifold. You guys who have already installed one, is this installed right? Is it going to give me enough range of movement so it can be timed?