How we should lift concrete blocks is a common discussion in the field. Rebar rusts and weakens. Cables are meant to be lifted how many times? I've heard stories of failure on cables, but I haven't seen it. I know it to be true with rebar. With rigging you still have to lift it or it gets trapped and it's a pain. The right solution is a ASME B30.20 rated mechanical clamp. A block clamp. 

The Eichinger 1562 Clamp found at www.CraneGear.net can be a good option. The sizes range from 0 to 47" wide on this clamp. Capacities are up to 8800 lbs. And it's fully adjustable as you can see in the video. There is another clamp that could work well too. The 1567 which is not listed on the website is a good choice for this work. If you know what you are going to be lifting, it's easy for us to just get what you need for the job. It'll quickly pay you back when you are working with a $500 and hour crane and crew. If it allows you to work with a forklift instead, it might pay back in as fast as the first day. If you end up wanting to look at other brands, make sure it's as automated as ours is. 

What's also cool is that we might be able to air freight it right to your door for an affordable price. If you want one in 7-10 business days, we'll have you covered so you can get to safe lifting.