Don't use JB Weld in the metering block! That is just asking for trouble. I have used it in ports with good success when cleaned properly, and roughed up, or staked, but eventually it deteriorates some. In a carb where fuel sits all the time, it would soften quickly and become a mess. You can buy jets in packs of 4, or in sets, or complete boxes of sizes from most parts houses. I you need the plates, they should be available, also. "Anything worth doing, is worth doing right." Joe-JDC.