I would limit the stroke to 3.875", 4" requires a fair amount of grinding and a real small base circle cam. Eagle has some stroker rods that are well clearanced for the cam. 4.155 bore puts it at 421, the difference from a 350 will definitely scare you first time out. And so you know, I have a 427 in the garage, built a 447 last year and have a 461 in my car now, I have an idea what it takes to build a stroker SBC.
