Given the parameters you've chosen, I would go with the bolt holes that match up with the where your chains end up when you lower the hoist to the block. Said differently, go with approximately the same distance that your chains attach to the tilter. But I don't think you could go wrong with bolt holes 11/12 + 13/14. You could actually do the same thing with the head on. Just remove and reattach those same head bolts. Additionally, depending on how high your hoist will lift, you may need to shorten your chains. Some set ups allow you to just move the brackets up and down the chains which would accomplish the same thing.