[LIforrelaxin]

I hate to say this but your troubles maybe just beginning. Now that the block has dislodged itself, it will likely continue to happen. Additionally I would be very careful using something like a vehicle to slide the block back into place. Your dock which I assume is still attached an up in the air could have damage from the original move, and further damage could happen with sudden move back to position. The quicker the block is moved back in place, the more momentum can be built up in the entire assembly, and you may find that out at the end of the dock there is some serious torque being created and causing damage.

I recommend something like this be down with a come-along, and the block be moved slowly....