In a true RICO layout, the pin should be in the middle of your span....the grip center, so whatever that distance is to your PAP is what it should be for all your RICO layouts.  The only difference would be if you're drilling it "Modified RICO"!  This is where the pin is positioned 1" above your grip center, but still on your grip line. The Modified RICO layout is used to move the bowtie a little higher so that you don't catch the finger holes with your track flare.  Hope that helps.
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George Pichl
PRO SHOP 300
Winnipeg, Manitoba
CANADA

It might go a bit longer but I don't think it will affect it much.  They recommend going up the same distance your PAP is up above the mid line.
In the post I saw on the Rico it says you can also move the pin to the right and closer to the PAP if you want a stonger reaction but too much tweaking will not give you a true RICO reaction.
I drilled up a RICO'd brunswick mammoth and the ball is awesome.  Super smooth and it will do exactly what I put into it.  It was my first rico ball and was a little afraid it would smooth the ball out too much and take away the backend.  I haven't had much success with pin down balls.  The ball actually had more backend than alot of my balls and it is 400 grit on drier heads and mids.
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16-17 mph
350-475 rpm
PAP 5 1/2 x 3/8 up
High Game 300 x 3
High Series 782
Book Average 215 / 205
PBA Xperience ave 180
years bowling 22