Welcome to the board - you won't believe how much GREAT info the group here will provide!! Cdowns & 67_C30 gave you some good ideas & looks like you've already done most of them.
I'm pretty new here myself (1yr) & finally started working hard to make my '68 a DD too. Could only get mine to run initially by pouring gas down the carb manually. Tank was nasty, lines were totally clogged, new pump & finally had to tear down the carb. OMG it was nasty!!
Rebuilt the carb & got it back on the other day. Another thing I decided was chucking the points ign in favor of an HEI. This was real easy per the FAQ. The little 292 is purring & sounds very strong now that the timing is dialed in.
Be patient & stick with it cuz it will pay off at some point. These trucks are so simple to work on & fix that you really can't go wrong. My 11yr old can't wait to take our first drive.