I'll go ahead and be the naysayer, Kevin. Look at how dark the top of the split is, it's already started to rot from the inside out. I ran into this a week ago with a lady having a Bradford Pear that split a little worse than that. It's already deteriorating from the inside out, the heartwood is compromised, at best, and fruit trees aren't know for being the strongest to start with.
Sealing it you might get up to 5 years out of it, best guess, but now it's opened for root rot as well. Seal it all you want, but the ground will transfer through any sealant you use and you will have rot from the top and from the bottom.
I may very well be wrong, and can't wait to get educated on how/why I am, but I honestly don't see any reasonable way of saving it.