[jmk]

Both motors, when functioning properly, will deliver the same HP for the same rate of fuel burn. The boat with the larger 8.3 liter engines carries about 1000 lbs more total engine weight in the boat, which will reduce fuel economy. So if all other factors are equal, that boat will be less fuel efficient.

Cummins CTA are physically larger than BTA motors, and in a boat this size access around them may be tight.

BTA motors are enough for this hull. Advantage of the CTA motors is they will have a very easy life pushing this boat.