I did this on a long pin tropical heat. Measure 13.5" from the pin to find the other side of the core .. use that spot as your new pin.. That should put the cg 4.75 from the new pin.. More than likely you are going to have to have a long pin to pap or have the pin pretty to the VAL, but it should work..
I was trying to get the ball to be longer and more angular in the back end.. not sure if it worked the way it should because I don't have another tropical heat to compare it too.. but mine is very angular on the backend.
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18 mph,350 rpm,PAP 5 1/2 x 3/8up, 10-13 deg axis tilt, varied rotational axis deg.. usually 45+
HighGame 300 x 5, High Series 808
Book Average 220,PBA Xperience 193