IMO you're going to need to use weights. I would put a 2 ounce 6' ahead and run 60' back. That should be pretty close depending on speed. You could also half hitch a 2 ounce with a rubber band 20' ahead of the lure and then run an additional 40' for a different weighted affect. Just keep in mind that using weights is very speed dependent in determining depth, so slight variations in speed will affect the depth of the lure. One other thing to remember is that if you're running weights and you make hard turns and are fishing close to bottom, the inside lures are going to drop like a rock and most likely become fouled with zebra mussels.