a 350 bored to 4.040 inches, with a 3.875 inch crank....which would be a 398

there was an article in HPP about some guy doin this to an LT1

 

It probably could be done, but you'd likely run into some serious rod bolt/cam clearance issues, anda may have to do something unusual with the rods and bolts and/or cam base circle diameter. I know the 420/426 SBC uses a 3-7/8" stroke crank, but that's in a 400 block already prepped for a longer stroke crank.