A bare BG would be all of 8,000lbs but would make one hell of a tractor. The OC12 gas would be a little heavier, depending on wether its a 4 or 5 bottom track wheel setup. An AG, or AG6 would be a bit lighter with good power also. These are bare tractors, with blades, I would figure an extra ton, give or take a couple pounds

Actually a later OC4 with the 3cylinder Hercules would be quite a tractor in my opinion. Parts seem to be more availible for this model too. With a blade I would think one would weigh in around 7k or 8k. I personally don't really like the HGs or OC3s for more than a farm tractor, or to push some loose dirt, altho an HG was our first "bulldozer", and quite a bit of road building, stump removing ect have been done with them.
Hopefully we have helped you.
Bob