What gas is better for my 63 tbird ?

If your old T-Bird is all original and hasn't ever had any engine work done in the past 20 years then you should be using a top grade Premium gasoline like BP/Amoco Ultimate or similar. Today's Premium gasoline doesn't compare to the premium of 1963 when lead was used in gasoline as a lubricant. A lead substitute available at most autoparts stores will help with "pinging" noise (valves rattling). But for a more permanent fix, you should have the cylinder heads rebuilt with Bronze hardened valve seats used for today's gas instead of the factory installed softer seats that needed a lead lubricant to work properly. Without the lead or lead substitute ( lead isn't available anymore because of it's danger to the enviroment). you will eventually need a valve job anyway to replace the softer valvetrain components. Send the heads out to an automotive machine shop for an "updated valvejob" and you will save yourself a lot of money in the long run. Plus, you'll be able to run any pump gas regular with no lead substitute needed with a new valve job (approx $400-$500) Some timing adjustments (turning the distributor clockwise or counter-clockwise for adjustment) might be neccessary either way. Good Luck, Kenny / MrBlueOval