have the top end off my '74 shovel for the first time. Heads are at the machinist. my question is about the pistons and cylinders. pistons are S&S 2500 series and mike out at
3.467". Bore is .030 larger. Pistons are not marked oversize. Manual says standard 74ci. bore is 3 7/16 or 3.437. Cylinder has OEM part number 16587-66. Could I have 80" cylinders on the bike? If so, do I order gaskets for an 80". And how and where do I get a set of rings? Amateur questions I suppose, but its my first top end job.

 

Your cylinders are probably 74 CI bored .030 OS Oversized pistons are usually marked on the dome look inside the piston also ? Stock bore onan 80 CI is 3.498

 

sqdeal was right on the money...found the .030 with a magnifier (very faint) on the top of the piston...ordered rings and James gasket set today. thanks

 

Good luck on your rebuild.
If your shovel still has the stock 6 point head bolts a set of 12 point aftermarket ones make it easier to tighten the hard to get at bolts.
Chrome head bolts always looks nice too IMO.