I agree about the Q Jet. A small 4bbl that I forgot about is a Rochester 4G series. This was the GM produced 4 bbl from the early 50s until about 1966. The model used on the power pack 283 should be in the ball park for size. I have only owned one of these carbs in my lifetime. It ran ok but I had someone with 35 years carb experience help me set it up. Very sensitive to float adjustment and drop. I was also told by people who were around this carb when it was new that it was considered "thirsty" on gas. A 302 GMC with a Q Jet or 4G would be pretty unique. In my mind a 302 GMC is pretty unique by ITSSELF in a good way. Jay