In my testing the 440-3 always worked the best. It worked better than a 440-2 with an adapter and it worked better than the 3x. This was on my old 514 that had ported EZ heads. That engine usually made in the 800-900 hp range depending on what combo we were running. For the OP's situation that info may or may not matter since it doesn't sound like he is looking for the absolute most power. I think an adapter for him might be the easiest approach. Some people report good results with the adapter but we never saw it on the dyno with our engine.