[lukecp]

I'm not sure what that vacuum hose is for, EGR maybe? It might be a good idea to post this question on the main board since it gets a lot more traffic. You also need to plug the empty vacuum port on the front of your carb, to the left of the large vacuum hose. You should be able to buy some rubber vacuum nipple caps in the Help section at an auto parts store for a buck or two.

Another upgrade that will make your truck run a lot better is getting an HEI distributor to replace your points distributor. It will start better, get better fuel economy, and have more power. You can get a used one at a salvage yard for $50 or so usually. You'll also need new plug wires, and the gap on your spark plugs should be increased to .045" or so. There may be a thread in the FAQ section about the HEI upgrade.