Cat fever, I went over to that thread and looked at how you constructed your box.  That's pretty dang creative man and gave me a good base line on how to build mine.  I'm going to still use a plastic 55 gal drum because I have one on hand, it'll be a permanent exterior mold, and I can leave the top several inches open to throw stuff in it.  I'll definitely mold a chainsaw scabbard in it, a must since usually if I have that ballast on I'll be clearing place on our land.  But this gave me something to go buy to put my 3 pt to the front of the ballast putting the weight farther back.  I think you saw some of the stuff I was lifting in my other thread about the tractor, plus when I unload and stack round bales of hay it'll really keep the rear planted.