to start with your "industrial engine" is designed to maximize torque at reletively low rpm, probably 4000 rpm max, not to be confused with a high speed performance engine turning 5000rpm +
think of your engine as an air pump, if it is 100% efficient, it can only pump 360 cu in of air per revolution, in reality an industrial engine that is optimized for torque is probably only 75% volumetrically efficient.
1 cu ft = 12x12x12=1728 cu in
engine displacement x rpm /1728 = cfm = volume of air that the engine can pump at 100% efficiency
360 x 4000 =1440000 / 1728 = 833.3 cfm of air that your engine can move at 100% efficiency, in reality you only need a 750 cfm carb to feed your engine.
all carbs are a combination of several systems, cold start (choke),idle, low speed, mid range, high speed and enrichment(accelerator pump), a 2bbl carb has and uses all of these systems, a 4 bbl carb has and uses all of the systems on 2 bbls plus 2bbls that are high speed and an enrichment circuit that are used at wide open throttle, ie, the last 10 % of throttle.
you need to be aware that if/when you start changing the intake and carb to increase performance you will also need to change the camshaft and exhaust to maximize the intake changes, in doing so the low end performance/driveability will be compromized.
my vote would be to keep it stock and enjoy the trip as well as the destination. if you really want more power keep your eyes open for an old motorhome with a big blogk 413 0r 440 ci engine with a 727 torqueflite automatic trans to put in your bus.
hope this info helps