Walboro's are known to fail every once in a while. I would definately check the pump and re wire the pump if it hasnt been done already simply to allieviate the possibility of it fucking up later if its not already. Also second the new fuel filter, its only a few bucks and its good to do.

Check the injectors with the multimeter like was suggested. If you are getting the proper reading and the cars still not running properly, i have a guy that cleans and repairs injectors (flow tests, o rings, the works) who charges 20 an injector. It might be a good idea to have them used injectors cleaned up a lil, and his shop is in Temple terrace so the turn around is usally a day or so max.

Other than that? well we'll have to go from there when we establish that the previous checks didnt resolve the issue.