Is this a daily driven vehicle? If so, I'd think long and hard before doing it.
You will lose fuel economy (not that it gets great mileage to begin with) and it isn't going to be a simple plug and play operation. You do mention you've got a MSD distributor, but if it is an EFI one, it won't work with the conversion unless it has a provision for a mechanical and vacuum advance or plan on getting an add on ignition computer for the MSD. In any event, it is going to mean having to set a timing curve, jet the carb properly (granted, there's plenty of data out there) and fiddle with it until it finally runs right. Chances are you can probably fix whatever relatively minor (EEC-IV is stupid simple to work on with the right tools) problem you're having for less money and trouble than trying to convert it to a carb, and have a better running vehicle to boot.
Just my .02