Hi , I had a '39 Deluxe with a Y block in it and I can tell you it ain't a pain free swap. You will need to cut the firewall , mine was back 2" but as mentioned here the '36 compartment is a little smaller and the radiator is tilted back as well, so you could figure on probably 4" out of your pristine sheetmetal. If you were thinking of mating it up to the Flatty trans, you'd soon find out they're not up to the task , even with careful driving. Best trans for the space would be a Toploader with the Jeep shifter , but you'd likely still have clearance issues around the center of your X member. The oil pan problem is easily solved with a pan and pickup from a 1/2 ton and up truck or the Tbird pan mentioned. If you use the timing cover from either of those engines you can front mount the engine and pick up the stock Flathead mounting points on the frame , but at the risk of driveline sag with all that weight being supported only at the front and extreme rear of the trans case. Best idea is to side mount to the frame using Flathead donuts on a fabricated mount that puts the mount out close to the frame rails so it doesn't put too much side load on the rails. It's all do-able but it makes a mess of your car for very little positive result. Best thing by far is a small block Chevy with the short water pump, it'll slip in there without making a scratch and preserve your precious sheetmetal , which ought to count for something. If you can't get your head around the GM vs. Ford thing.....seek professional help
....or paint the Chevy a Ford colour and fit some Yblock valve covers to it and tell folks it's a Yblock.....
....most won't know the difference....regards, Col.