this is indeed a great thd.
when drilling a hole to close dimensions,if you drill it.01/.02 undersize then use correct size. should be close .002/.004 over.
old endmills make excellent boring bars. needs to be on center with the cutting corner on center. careful not to drag the flute in the bore. our ancient bridgeport had table shake real bad. i started using 3 flute endmills and it helped alot.
on the 4jaw chuck. permanentaly mark 2 of the jaws that are 90' apart. when you remove a part,loosen these two. when you put it back tighten these two. mark your part also for 2 jaws.