Taking a different and probably more unpopular route here - you are not over cammed. You have either a tuning issue or base engine problem. It should idle like a kitten with that camshaft. I won't dispute that you should get a positive result from a modern convertor - but not because the engine's running the way it should. You'll still have a doggy engine in front of it. If a 4" stroke has less duration than 250° .050 it should idle under 800 easilly and it would work with even a stock low stall convertor. The ones I build get decent mileage in addition to opwer because the convertor is tight.
In regard to the stock lower end -
I agree it will never be built. The problem I see is no piston would work on that "stock" combo shortblock and a cam you would need to run. Even a 7.5:1 piston .125 down will hit a 2.08 valve with a big camshaft. You need some valve pockets - and then you've just upgrade the bottom end.