I've built a couple strokers (4.062 stroke, 5.7 rods) at 4" bore in a 250 block. No breakage but there was evidence of bore distortion.
Latest build is at 3.935 bore (4.062 stroke, 6.0 rods) and seems much more stable in terms of bore distortion. Pistons are very short custom JE. I've run it hard without problems.
Search for "Nova project progress" for more details. I don't know how to attach a link, perhaps someone can help
Here it
IS.
