Cost is definitely a big factor in this that I may have left out so far, as well. At nearly $600, the 750 ultra double pumper is about $230 more than the other two carbs I'm looking at. I feel like it might be hard to justify this price if the only difference is 10 HP extra at the top end and worse fuel economy. But again, I don't know enough to know if this is actually true. I've seen people say the edelbrock style carbs are more fuel efficient without sacrificing power at the low-mid range, but is that true?