fuel line question

The 3/8 barbs are available, maybe your NAPA didn't have them. You could always get one of the glass fuel filters, they come with different sized screw in barbs that go into each side of the filter. Probably a lot cheaper than going with Edelbrock's kit.

I put 5/8" heater hose over the 3/8" rubber fuel line from the pump to just above the alternator. I've always thought there could be an issue with rubber if the alternator belt let loose. Had a car fire 30 years ago, been a bit paranoid about fuel lines and will never buy a "great" used carb ever again, especially from a friend!!