Paulie,
I just noticed this post.

1st, Get yourself some regular copper core Motorcraft plugs.

2nd, Whether you have the Unilite w/ vacuum advance or not, personally I'd get rid of it (these things are made to run 15 seconds at a time on a dry track) go to the junkyard and get the correct Duraspark II ignition box, distributor and associated wiring.
Install it and call it good.

Obviously the P.O. didn't know a thing about ignition timing. God know what he has for springs and limits in there.

It really sounds like a timing issue and you're better off not dealing with someone else's headache.
Hope he didn't do too much internal damage driving it like that.

Aaron knows his stuff and has given you good information so far.