i like 4.25, they are tight but playable and you will feel like a god on most regular tables after even a few hours of play. no shims - extend the subrails. if you need more info contact mark gregory perfectpocketz - or glen realkingcobra, and they will help you make a decision. if you want i have pics of a gold crown 5 mark did here in GA. i can show you. i have posted them here somewhere before.
I'd love to see those pics. Nothing like a quality tight pocketed Brunswick....well, alomost nothing anyway.