I'm on the rack side. Two comments
If your load is all Paper at 40 x 48 x 60 it weighs a LOT more that 1000# more like 4000#
If the load is unstable and leaning, it may start the rack leaning and then you will have real problems. All rack relies on being plumb and level but with Drive in there is NO room for error. Drive In has no inherent L-R stability.
What kind of business are you in? Newspaper inserts or magazines?
I can help more with the racks with pictures or specs etc

Jeremy, let me know where you are and we can possibly arrange a visit to see the exact application. Seeing is the best way to know what you need.
Call me at 610-751-3208.

Jeremy, sounds like you need a load stabilizer attachment. We make these and I can send you information on specs and purchasing. call me at 832-640-2721. We can build to suit or offer standards that meet your needs. Your problem is not at all unusual.
Brian
Unit Load Handling Systems, Inc.
Alvin, TX

some pallets are wrapped fully, some are wrapped on the top and some are unwrapped

But they pass by any wrapper line or shrink line before you stacked then?

The pallets are in bulk of relatively the same size which are stackable, however they are relatively unstable.

Are the pallets in bulk or in reams? All the pallets have the same size?
Can you stack the pallets?
I work in a pulp and paper company and i could help you if you want!

the pallets are very unstable because they have paper stacked on them, i estimate they weight about 1000 lbs each at about 40" x 48" x 60". The other problem is they are not being shipped directly, they are kept in storage to be finished so shrink wrapping wouldn't be the best solution.

what are you lifting? Whats on the pallet? How much does it weigh? Dimensions? Cant you just use shrink wrap?