[Ironangel]

I'd rebuild the carb to small V-8 specs and put it on a new 1/4" gasket. The Quadrajet will get excellent mileage if they're set up correctly. A Quadrajet set up for a 454 would most likely be rich and foul plugs. Your timing needs to be determined and verified when you get the carb rebuilt. There are short rubber hoses that connect the fuel and vent lines under the cab. Make sure one of them isn't cracked and leaking fuel. It's always a good idea to buy the Shop Service Manual specific to your year of truck, https://www.classicparts.com/1968-Sh...ctinfo/04-026/ It will have the carb tune specs and much more necessary information.