Hello everyone. I have a Renegade 31 that I'm going to repower with a pair of Mercury Verado 400R's. How many inches should the anti-ventilation plate be above the keel bottom line? The bracket has 26 inches of setback. Would 2 or 3 inches work?

Rule of thumb is that you should raise the bullet of the engine 1/8" per each inch of setback. In high performance applications we don't use the cavitation plate.