rod length for 3.78 stroke crank

depending on what bore size you will be running but you can get a piston with a 1.45 CH normally on a 4.0 inch stroke with a 6.125 rod but just buy a 6.25 chevy rod with that stroke crank you have and it will work you may have to deck the block or buy a 18* chevy piston with a 1.56 CH. and run a 6.20 rod.