The reason we made heads with Pan pattern was that we could use Axtell Pan cylinders. We do not make those anymore. All our heads and jugs, stock to 4", are Knuck. We do have 3 5/8 Pan cylinders coming soon.
Axtell will no longer build Knuckle cyls. S&S did at one time offer Pan headbolt pattern big bore cyls for Knuckles. I have an un-used set. With Flatheadpower big bore cyls. available, the only way I would run the Pan/Knuckle cyls.is if I had already converted my heads to a Pan pattern.
Larry, We use the S&S cases as they are, up to 3 13/16 bore. For the 4", bolts will have to be moved, material left by the rear tappet guide and the guide machined instead. The upper casebolts will have to be moved apart for the 4 1/4 spigots. We now make 4" Knuckle jugs and heads, so I hope we can get the cases the way we need them. We have officially stopped making any other bolt patterns than Knuckle.
Well, we do not tell our customers to take it easy with cylinders or any of the parts. As long as they´re installed correct and properly broken in they should perform good. As to Mom going 132", it´s only a matter of 5 1/4 stroke and 4" bore. She´ll be a nice street Mama.