Attempting to maximize this dwell time lets say we take the 4.6l crankshaft, drop it into a 5.4l block, and get connecting rods made up so that the piston reaches zero deck due to the 5.4l being a taller engine , we can almost gain 1 full degree of total dwell time.
Would it be worth it? Probably not. Given the rod grew over an 1-1/4 longer, adding weight and anytime adding weight, its not a good idea.