You want to put it within 7" or so of the centerline with 5-6 FEET of unobstructed hull in front of it. PP has all kinds of instructions, these are from my site when I did it on my direct drive Toyota. You will need to find the right spot on your hull, make sure it is not on top of a trailer bunk. I put mine in the back in the Vdrive location, pics are included.
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http://www.epicmarine.com/docs/Toyota%20Epic%20Perfect%20Pass%20Install.pdf</url>
PP is the best money you will ever spend. I'd rather ride behind an IO with perfect pass than a SANTE with a crappy driver.