I spent a dozen or so hours this weekend wrenching on stuff...
Got the pedal mounted at least enough to drive this fall. I'll eventually try to rig up a better bracket so the position is a little less angled but it feels comfortable where it is and I get full range on it. I ended up cutting the bottom of the pedal off to clear the floorboard. I'll eventually build an offset mounting bracket so its less ugly... but it works.
The Yukon has been battling me just constantly trying to get this engine out. I tried to save the harness but that wasn't happening, so I finally just cut it out of the way. Now I've got a bunch of scrap wiring for when I need it, so that's not a bad thing either. I'm down to the torque converter bolts (late 4L60E so I have to go in at the starter) and bellhousing bolts. If its not pouring rain after work today I'm going to try to at least take a stab at this, probably take most of the bell housing bolts out at the very least.
No photos but I also dropped my trans crossmember out. My crossmember has a support bracket that runs from the upper part of the frame rail down to the crossmember itself... well, it looks like whoever did the 350/th350 swap, when they moved the crossmember forward, did it with the cab off... they put the bolts in top down with the nut on the bottom, so there's no way to get the bolts out without lifting the cab. I can still move that brace, so not that big of a deal... but given that 5 of the 9 bolts that hold that crossmember on were less than finger tight, and really, really poor quality hardware, I am glad I am reassembling all of this. I've already gone through and made sure the front and rear suspension bolts are all actually tight and not finger tight.