If you're going to run a 4.15 or 4.25 stroke crank in a low deck then you'll probably be more successful if you use a chevy pin on the crank and an off the shelf 6.535 chevy rod. The 383 rod is too short to work really well and the 440 rod is too long to fit.

The 383 block, 440 crank, LY rod and short piston combo is a great low buck setup that should really run hard. 10:1 CR with a set of E heads will make a very, very nice motor.

I need to hook up with Todd and get a set of those pistons for a mag article. Maybe throw in a set of Brandon's $400 rods just to see how well they like lots of dyno pulls.