I will add that I checked my PM1340GT headstock alignment the other day after the discussion here, each chuck had a different run out at 6" out. I use a 3/4" Tight-Tolerance Rod Precision Ground 12" put in the chuck. Level the machine as Ken describes. I use a 4J Bison chuck to get as close to 0 TIR reading at the chuck as reasonable possible, the dial indicator I use is indicated at 0.0001" per division and barely moves. At 6" out, I take the average of the swing, which is +/- about 0.0002" on either side of zero. If you do not take into account the swing of the shaft due to to different chucks or the shaft not being perfectly straight your head alignment will be off. What I had read was to take the average of the high and low dial indicator readings at different points on the rod, the 0 point should swing evenly around 0 for alignment to be correct. My 5C chuck is worse, and runs around +/-0.0005" at 6" out. The alignment is pretty much spot on after tweaking the head alignment. A 5MT test bar would be great, they sell a 5MT on eBay for around $115, they say they are accurate to 0.0002" or better. But a lot to spend, but can also be used for your tailstock alignment. I am still a newbie at this, but it has worked well for me.