stroke

what is the largest stoke crank that can be put on a stock 460 block and what is the max hp. it can handle

max stroke is 4.500! and hp 800-1000hp for the block!  

Well..... That's a somewhat loaded question.

With out a bunch of grinding typlcal stock blocks will take 4.75 stroke with steel rods, that also gets to the realistic limit for typical ring packs with commonly avaliable parts at 10.300 deck.

As far as hp goes IMO stock stuff gets dicey above 750hp for reliability, but plenty of people have use them much higher with varying results, myself included.

A lot depends on good machine work, proper assemble and tuning to get stuff to live.