we rent the tool and of course we can do it in house, but it is difficult even with the tool that we have even changed to make easier. if we were to do it in house we would cut the spindles off and bore them on the lathe then put the boring bar on it and weld them back on straight. way easier.
i would say all 8 bolt hub 60's can be bored most of the ones i have seen that can not are 6 bolt shafts if thats the case your 70 shafts wont work anyway. also the ones that wont bore dont take a regular spindle nut they take a small one like a 44.
just measure the OD of the spindle subtract 1.560 if you have like .060 left you certaintly dont want to bore it.