First off what size leadcore are you talking? There are different #. I fish the east end from Buffalo to west of Dunkirk and use leadcore exclusively. 27# from 2color through 11color. I run 30# braided backer and 60' to 70' of 15' fluorocarbon leader. With a 100' of backer let out you run in 6 to 6.5 depth increment per color at 1.6-1.9 speed. 6'-harnesses, 6.5-shallow diving crank like a Renowski. The consensus is 5' per color but speed, what #?, type of (mono or braid) and how much backer? All have there difference. You add a deep diving crank to the equation? I would test like someone else suggested. The most important factor period...is knowing what depth your baits are running!