Pin over will go longer with more of a flip, but is not a true oil drilling. Please refer to the drill sheet for the MMachine. If you know your PAP coordinates, you can choose the appropriate drill. If you are a true low tracker(<3-1/2), pin over bridge might be close to leverage (3-1/2 to 4). Pin under would make the ball read the midlane earlier, but less backend. I don't know what you definition of heavier oil is?? It is hard to have a ball set up for heavier oil that has substantial backend especially for a low tracker/revs/speed. As I said - give Carl a ring.
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Gary