[bigj-dog]

Check ebay for the cheapest headers, otherwise Jegs/Summit Racing, JC Whitney also has a good selection. As for the gas cap, you can try a vented one from a junkyard to check, or go to your local gas station and ask them to see their box of 'left on the pump' caps. If it's supposed to have a non-vented cap, then you'll have to check the tank for a vent hose that may be clogged up, thus causing your hiss. You can also check Ebay for a Q-jet book, or Chilton's/Haynes' Manuals or Amazon.com, they're not too bad to work on, but most people will tell you to buy an Edelbrock to save yourself time and headaches, as they are much easier to tune.