Man that is some big wood!! You gotta take pictures of it (next time you do it, or whatever).
If it is western white pine 60" x's 5' is 3750#.
You would need at least a 1" rope(double braid around 44k abs), 1 1/4" would probably be better. For a sling, I would use (for the block)a 3/4" (52k abs) amsteel sling, unless you use a loopie, then you could use 5/8"(40.7k abs).
For attaching the bull rope to the piece, a bowline followed by several half hitches would work, or you could use another sling (1/2" amsteel would work in a loopie) and a large clevis.
But then the big problem in my mind, what are you gonna use for a friction device?
If using a crane, either there slings, or amsteel ones for peices that big, without all the extra weight and hassle from steel ones.
