Skintback, I am not an expert,but I believe with the 60 you will for sure get on plan quicker,as far as rpms are concerned they can be changed by the pitch in the prop,also one on the 60, trim and tilt plays in on top end speed also, where as the the 40 probably dosen't have it. Also you didn't specify the boat your're putting it on,is the hull weight the same or more then your friends boat.

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Georgia Slab Masters Tournament Trail
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