Stacking Racks (of different sizes)

Hi guys,
I got my first rack a few months back (28qt. 5 tub rack). I am planning on ordering a 3 tub V70 rack soon and was wondering if anyone has ever stacked racks of different sizes?

Also, does anyone stack their racks ontop of something else (i.e. a home made stand or something similar) to raise them off the ground? (heating reasons) if so, I'd be interested in hearing what you have done in the past.

Thanks for your help and time!

You should be able to stack racks without too much trouble. Just watch out for sagging in the bottom rack. A sheet of plywood or something similar might help to spread the load out on the bottom rack.

Thanks!