Carb Choice (New 318)

I always select the biggest carb so it can be used on other projects while working at a gm dealer in 85/86 the astro van we used delivering parts had a 4.3/262cu in.engine 835 cfm Q jets that were adjusted for the 4.3 engine the air door on the secondary side was set tight metering rods were smaller to allow more fuel flow at a smaller opening and had great fuel mileage and power the best of both worlds