Ken,
sorry to hear this. But as the guys have said, don't count it out yet. Do some checking and find out what it is.
With the uneven cranking, this tells me some of the valves are not opening. This is a sign of the cam not turning when the crank is. This could be as simple as a timing chain failure, or maybe even a broken cam, which I doubt. If I were guessing, I'd say timing chain/gears.
It's also very possible you have a keeper off a valve spring, but I don't think this would keep it from starting. The timing chain would and it would cause a bad uneven cranking. Pull the front off the engine and see what's going on. Pull the distributor cap and valve covers first just for the fun of it. This will tell you real quick if the valves are moving and the distributor is rotatiing or not. If this checks out, you have other problems to worry about. Let's hope it's not a rod or something worse.
But you know what, it sounds to me you are bad wanting a 454 HO engine.
I can't say I blame you on that one though.
Good luck with it and keep us informed on what you find.