Ive been thinking its something with the ignition, what distributor do you have in it? If the shaft is wobbling it can cause intermittent problems like that, so can a cracked reluctor.

 

Well I Took the carb off and it had a lot of reddish/brownish sediment in it. So I soaked all the jets, re-cleaned it and today it ran fine for about 20 minutes. It still seems to be running fine, so I guess I'll see how its running in a few days...

Oh and by the way I have a Mallory Unilite. Theres no play in the shaft whatsoever, and the contacts are clean. Ill keep you all updated, thanks so much for the help and ideas.