New P & C sets are a must for a rebuild. Re-ringing is asking for trouble! Stock sets are cast, and HP sets are forged. We will not sell sizes that compromise engine life. YOU MUST CLEAN BEFORE ASSEMBLY!If you are using a Big-bore set for a T-1 style engine, pay attention to the "stroke" selected. You should use the "A" (short stroke) sets for 69-76mm strokes, 78 and longer strokes should choose the "82 Stroke" version. "A"s have a much longer piston skirt, and a taller pin height. If you try to use "A"s on a 78 or longer, the piston skirt will interfere with the crank at BDC, and clearancing (and rebalancing) is a pain you can avoid by using "B" pistons.
If you use "A"s on a 76mm stroke for example, you can get you deck height back to "stock" by installing cylinder spacers, 1/2 the stroke increase. In this case, 76-69=7mm, 7/2 is 3.5mm. 1mm = .040", so that means you need .140" worth of cylinder shims (and longer pushrods) to get back to the same deck height as before.
Case and cylinderhead boring sizes are as follows:
85.5mm, 87mm Slip-in, and 88mm Slip-in: 90mm Case, 93.8mm Head
88mm Machine-In: 94.4mm Case, 97mm Head
90.5 & 92mm Machine-In: 96mm Case, 98mm Head
94mm Machine-In: 97.25mm Case, 101.1mm Head
