Depending on the specific year of the motor, a spread bore carb would have been the Carter Thermoquad, the late 70s and early 80s got a Rochester Quadrajet. Both were love/hate carbs. A guy could also use a spread bore Holley.

As long as I wasn't into listening the spread bore carbs howl, I usually got better gas mileage from the 4bbl then most 2bbl carbs delivered.

I also would not be4 too concerned about the guys that would complain about the 4bbl conversion, they will already have their nuts wound up tight because you have installed the )D 4 speed. What ever their opinion is doesn't really matter, they are not the owners of your truck.