J,
IMHO, 5-8 isn't enough. Put 10-12 on it and maybe even more. More lead, to a point = better vacuum signal. Additionally, you can close down carb primaries and clean up your idle settings.
Down side to put a bunch of lead on the crank, you may have to limit distributor advance by jb welding up the wieght slots in your distributor.
I ALWAYS like to put as much lead on the crank as possible without, pinging, run-on dieseling or starter kickback.
Screw the old man... tune it in the driveway before 10pm... stupid old pruney bastard. :thebirdm: