What is right X dimension
 

I am running a Baja Hammer with about a 500 horsepower 468. It has a standard X dimension. The propshaft is about 7.5 inches below the bottom of the boat. Currently I am running a labbed 25 pitch Mirage plus. Hole shot and mid range is great. I am considering going to a shorter lower unit. How do you know how much shorter you can go? Trial and error is a little expensive. If I went with a 2" shorter lower and changed to a Bravo 1 prop would I still be able to pull a skier? Appreciate the help.

probably.

Ok, I'll give it a shot. It sure sounds like your drive is really deep. You should see a good speed gain by going to the shorter drive. I'm pretty sure my old boat was higher than yours when I went to the shortie, so the blow out problems should not be an issue on your boat. As to pulling a water skier...well, anytime you go higher the boat definetly will not plane out as well. If it's questionable now, you proably won't be able to get them up after. Even with the long drive, my boat was too slow to plane to pull a skier up. However, a low pitch high five, bravo 1 or a Mach stern driver with some extra cup sure would help.

Right now, I can rip their arms off if they can hold on. I get a great hole shot with a labbed 25 Mirage plus. I realize if I go shorter I will need to switch to a four blade. I just don't want to end up having to work to get on plane. Currently, I have no problems. It does go on plane faster with the tabs down, but it is still pretty quick with the tabs all the way up. Is there any right distance below the pad keel, or is it simply trial and error. The bottom of a Hammer is very conventional. No notch transom, and no stepped bottoms. The keel is flat and about 4" wide.