I just bought a cheap heavy duty engine stand and fabbed up a plate the bolts to the exhaust holes. I then welded it to a tube that fit inside the tube in the stand. Works great unless you have the exh manifolds attached. There are folks who sell that exh plate.
Ford Flathead 85-100HP 59AB/8BA Engine Stand Adapter *Fits standard eng. stand with 2-3/8"opening. Other sizes available,
email me with your size needs if different. Not responsible if
not checked.* Comes with mounting hardware ..............$80.00
This is my Flathead Engine Stand and I find it very useful. Notice in the first picture with the Engine in the Stand, there is a Pin that you can lock the Engine in 4 different locations, so you can turn it upside down to work on the Bottom End, or you can lock it in so that you can easily mount the Flywheel and Clutch Plate. The Motor is very well attached on both side that really give it good support with no chance of damaging the Block.
cradle stands are the go but lots of luck finding one and then getting them to part with it is another mountain you need to climb as a lot of them where converted into truck diff rebuild stands and are the bees knees for that job