I think you're making this far more difficult than it should be. You're going to want to be over the action and watching how things line up not in your truck pulling a car over top of your motor. It still is slim fit dropping that down on there.
I think if you just Jack the motor up in the air like you said and rolled the car underneath it like you said all finished and done headers waiting this would keep it simple.. do yourself a favor and put the cars wheels up on two by sixes or something so it rolls easily and you're not trying to lug it through the grass.. or at the very least if you're going to try this silly put it on the k frame and roll it around on the ground method put a big sheet of plywood down there so you can simulate a smooth floor...
