Those designs were just to basically wrap up what I wanna do in a short statement. I designed them as like a starting point. I used them as a reference to build the frame but did not go 100% by them. and yes, that is a vertical engine you see. It is an old 16.5HP Briggs from a mid 80's MTD. I will be using my old transaxle from my derby tractor on this. On the transaxle, before it went into the derby, I ran a smaller drive pulley on it so to be safe, I took the casing off of it, welded up the gears to make it a 2-wheel drive in the rear, I replaced all of the lube with a transmission/hydraulic mix(I made) and in the derby, it ran perfect and didn't get hit hard so Im gonna use that. I believe it should run fine with this setup but I'm gonna extend the shafts about 8 inches on each side and mount some bearing to them for support so I don't flex the shafts and mess up the transaxle.