Originally Posted by wavelength
you would be better with the engine off set 1/1.5 inch to the right to counteract prop effect
I have a similar size/ weight / HP and mine's dead centre - no chine walk or biased steering offset on mine.......
If your engine is fully down, I doubt it is even chine walking - for what it's worth as an experiment years ago I had an SR4 with a 25 on the back, and made it do exactly what you describe by putting the trim pin (no PT on that!) at the lowest hole. Opening the throttle felt like it was trying to do submarine impersonations, the stern lifted and it wobbled to & fro as the bow tried to go underwater!
Before you start mucking about & / or spending buckets of cash, play with the trim!
Eek it up slowly until it starts to ventilate (cavitate) then notch it back down a tiny bit. You'll hear the engine star to "sing" as it hits the optimum trim position. There is also an argument for raising the stop pin up a couple of holes to prevent this happening accidentally if you are not paying attention. (mine is 3 holes up from the bottom, for what it's worth)
Also here is a description of chinewalking I wrote recently: Chine walking