Stronger Crank? - Stock Forged 3.31” vs. Aftermarket Cast New 4”

A forged crank period is the better way to go either way. Plus I wouldn't trust and eagle cast crank with anything (do a search on here and you'll find eagle cast crank failures) that said they do make great forged cranks though. I have a forged stock stroke eagle crank in my 340.
Oh yeah something else, you'll get more miles out of the block with a stock stroke then a stroke because strokers beat on the cylinder walls bad.