I have one of the old style here also, It's a bit hack, but I just stubbed a short piece of tubing 6" long with one end partially plugged , then pluged it into the hole where the tall vent plugs in and made it goose neck up over the filter. This blocks fuel from coming out, but lets air in as the tank is drained. Doing this it will run fine with a new bigger 260 filter. You can just change out the top cover on the carb and then it will have the intelicarb feature, otherwise just block off the inteli hole in the filter and run it old school. If the filter gets dirty it will run a little rich thats all.