340 crankshaft stroke

I was watching a car TV show, forgot whcih one, and they went to Egge for a tour. There custom pistom makers for old engines. Like Old HEMI's, early V-8 Fords, flat top Fords, etc....

They use a calulator to figure out custom piston diamentions for any given stroke.
Use of a stock piston is possible if you have a understanding of how to shorten piston skirts and crowns for clearance.
Otherwise, at best, a stock piston will only take a modest increase in stroke and work. But work how well is the question not to mention how long.