If you want to get picky. You can use two sets of gauges. Take a marker and put parallel lines front to rear across the pad. Then measure on each line.
Put one gauge at the front of the straight edge, say .060 and then use the other to see if the clearance, .060 is the same front to rear. If you decide to make a change, get ahold of Bill Smith, he might send you a drawing of the tool he contrived.
If it runs on a string I would try to dissuade you from changing it.
Mine didn't and I tried alot of things to make it better. Moving stuff around in the boat different setbacks, props. It didn't lean to the right, it dropped. In my case I tried to get info on here but had very few replies. In my frustration I took it upon myself and did the deed, :cuss the lip. I lost 5mph. Then I started jacking the motor up 1/4" at a time and drove the boat in all kinds of wakes and waves, speeds and trim levels. I was over an inch above the pad when the Old Sack O Cats hucked a rod through the block. At that point I had gained 6 mph and it drove great.
While I was waiting for the rebirth of the Sack O Cats I cleaned up the whole pad. Made everything square and filled areas to make the edges sharper and uniform. Someone had done a few "repairs" prior to me buying the boat and IMHO caused the unruliness.
Now I have run it to 100.5 mph, that was a quick blip of the throttle 2/25 of a second, from cruising about 95 with a 29 SRX. About a month ago I was picking on a fairly fast Jet boat when my engine shut off at about 80/85 mph. All of a sudden the boat was turning to the right and not really reacting to my input of turn left to straighten out. I then realized the engine wasn't running, I thought I stuck it. What happened was the dock bumper that I have tied to the passenger handle had floated forward and came down on the toggle switch for the ignition thus shutting off the engine.
This is my interpretation of how the lip works. As with any V hull as the boat is pushed through the water the boat is pushed up or squeezed up by the pressure of the water against the V. The front and sides of the hull start to be lifted by the air. The water pressure against the lip becomes great enough to lift the transom thus tripping the boat. The air again lifts the bow of the boat. The angle of attack is what makes the boat slower or faster. If you can poke through the air cleanly the boat will fly like a air plane wing. The distance across the bottom of the boat is shorter then the top. If I have the rear bucket seat in the boat the vacuum in the passenger area will pull the cover inside out, also it will lift and pull the seat out of it's pin socket and the seat comes forward to my right.
http://forum.allisonowners.com/showthread.php?t=8357&page=2 Pic's
Look up the Allison hull patents. There is some good reading if you can envision it.
The Jasper pic is an XR2001 that was second to Dave
