To the best of my knowledge, I don't think you are going to find the correct 4 Bl intake for a 66 283 in a truck as they did not offer a 4 bl until about 69 and that was a 350. Probably the ones you have seen on other trucks are either aftermarket or from a passenger car. There is one metal line with a vacuum hose attached that goes from the carb to the distributor vacuum advance. There could be a line to the choke also. Fred


1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes
1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes
2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans
1947 Willys CJ2A w/F-Head engine