383 uses a 400 crank (or it can use a stock one), so that has been done for years. 396 uses a 4.125" aftermarket crank, adding to the CI but also adding to the cost. You may have more issues with the longer stroke of the 396 (rods hitting black and/or cam). You also cannot use as long of a connecting rod on the 396 as the 383.
I would possibly PM Dynamic396, he's in the process of building his own. I'm surprised he hasn't commented to be honest.