Does anyone know what the end play spec is on the cams in our engines?

As an aside, the first really good service manuals available for Indians are the military manuals, with full specs and engine rebuild procedures. Well worth hunting down a copy, should be available to AMCA members in their virtual library, will check later. 

Everything pretty much directly relevant to 101s, altho they do talk about 0.003" clearance on the pistons, which is tantamount to inviting instant seizure on a total loss bike, and tbh sounds a bit tight even for a recirculating oil sidevalve motor. Assume they had a really course stone for final honing and the military altinized piston rings, which were designed with a soft coating to bed in fast, so the peaks in the bore would probably be worn in a thou or so within a few minutes of running, giving a nice serviceable 0.0045".

Yes, 003 too tight . The pistons come in at 3 thou under , ie standard bore 2.875 and piston 2.872" I have seen 2 sets of repro cylinders in the last year that have been set up at that, and have signs of rings seizing in the lands after a few miles, and piston galling. I have stories of half a dozen more early failures. If you are going to be really careful and gentle running in, 4 fine, I aim for 0.0045". In a conversation a long time back with Fuzz, a master motor builder and long time member of Reading Motorcycle Club, ( been gone a few years now ) I asked him what clearance on the bores he would use, and he said 4 if its me running it in, 4.5 if its a guy he trusts to listen to him, and 5-5.5 if he thought the guy would nod sagely and ride off up the road at full throttle on a fresh motor.