Not really a 'storage' stand - and it doesn't exactly conform to your requirements of support via the oil pan rail, but I'm in the process of building a run-in/test stand using a spare T frame and A cross member I had laying around. Basically, we used the front 42" of the T frame for the top piece (with an A cross member welded in) and the rear 42" of the T frame for the bottom perimeter. 1/8" 1x3 tubing forms the uprights, and we'll be welding 4" U channel onto the top of the frame rail for the 'ears' of the flywheel housing to rest upon. Total cost - $60 (materials and heavy-duty casters).
The A cross member allows for radiator mounting and we'll be fabricating a battery box, mounting a fuel tank, and adding a 'control panel' for temp, ammeter, fuel pressure gauge & pump, and oil pressure gauge. I figure this will allow initial run-in of my newly rebuilt engine and serve as an adjustment/tinkering stand if/when the motor ever needs to be pulled. I think the extra 8" or so of width are worth it to ensure that I can drop the pan if I need to....something to consider (and since I had most of the materials available, it was cheap)
