A good radius in the fillets is mandatory. The BBC rod mod is a good thing. Using Icon 428 pistons and shortening the stroke up about .050, the 6.8 rod is just right. Be sure the grinder understands "radii" AND offset-grinding.
The oil chamfer is also a good place to "help". A leading trough on the main and a trailing one on the rod does the trick. No sharp edges.