A special two-piece aluminum manifold casting was used on 283 V-8s equipped with fuel injection. The upper casting contained air passages and air/fuel metering system bases, while the lower casting made up ram tubes and covered the top center of the engine.
A major engineering development is never simple - or easy. And although the introduction of Ramjet injection was a milestone in Chevy history, bugs were inevitable. At the Daytona Speed Weeks, for example, the fuel cut off during acceleration characteristic was eliminated because this created a flat spot in response. Fuel nozzles, too, required attention. They were extended further into the air stream to prevent them from absorbing too much heat and casing rough idling.
There were no formal published tests of the fuel-injected 283 in a standard Chevrolet, but performance of the "fuelie" in Corvettes is worth mentioning. The 0-60 mph acceleration times of the most potent versions consistently averaged just over 6 seconds, and top speeds were in the region of 140 mph. Driving a 250-bhp FI Corvette (33 bhp below the 1957 maximum), Walt Woron of Motor Trend magazine whizzed through the 0-60 sprint in just 7.2 seconds. With a special 283 sporting 10.5:1 compression, dual exhausts, special cam, and solid lifters, the car did 134 mph, and convinced Woron that even at that it wasn't really extended. Extrapolating from these results, a two-door sedan weighing 400 pounds more than the 'Vette might have done 0-60 in about 8 seconds and hit a top of 120 mph with the right gearing.