You might also have multiple issues. My '65 GMC's 305 has been running like crap for a while (many of the same symptoms as yours) and it seems to have been a combination of the Stromberg needing rebuilt, a vacuum leak at the brake booster, bad points, the plate inside the distributor being displaced because of a bad set screw and a fuel pump diaphram that disintegrated and precipitated the whole cascade failure.
I had to fault check everything. Maybe you should, too -- you might find you have more than one causal factor at work. Check every system -- even if you think it's good. fuel system, electrical system, vacuum (all of it) -- verify good and move on to the next system.
Good luck!!
John
