The spindles standard are 0.001" larger than the bore of the hole in the case which is 0.500".........This amount of interferance is plenty........so if it was 0.0015" over it will be a very tight fit in the case, especially if you dont fully heat the case in an oven. The smaller follower spindles run even less amount........i find it best to make up a go/no go guage of some form.......if this is able to slide into the hole and not wiggle around at all, then if you add another thou that will be plenty.......If the spindle is too oversize it can actually cause a crack to appear at the top of the crankcase where the barrel/ muff sits down.........Bush clearance, well do not be tempted to make them too tight a fit, it is not uncommon for them to grab the spindle and spin it in the case.......Unfortunately when you press on the pinion gear it tends to crush the cam, thus causing the bush also to become smaller in the ID.......Thus it will need honing out.......you can use a sharp reamer, but it needs to be in "As new" condition........all the talk about the poors of the bush becoming an issue is more likely a case of "Overthinking" i've never had any issues with it........just make sure it is thoroughly cleaned out and oil the bushes upon assembly........Ideally the inboard bush should have a radial cut groove within the bore to align with the hole in the spindle, thus allowing much better oiling of the inlet lobe/follower instead of the factory "Timed squirt" which is near useless when you think about it.........good luck with it all........Cheers.
