The only difference is the x axis feed and the paint job. Trust me they are not going to change much. The spindle housing is the same one since 1990. I can tell you for a fact that it has not changed.I am using a 1990 spindle housing I got from JT on my tri power since the original was a piece of junk. All the castings are made at the same foundry. JT is filling you full of bull. Where are the needle bearings located. And are the spindle housing bearings p5 or better? Ask JT for a complete list of upgrades and make sure he is telling you the truth before you buy. A fancy paint job and a different x axis feed is all I see. We can convert our machines once we see what they have done. The fact is the first machines were machined much better than the ones now. Also I paid $2400 for my machine you are paying way to much for a few upgrades as for the manufacturer it's a lot of crap. The same kind of people are assembling the machine. The parts are still being casted at the same foundry.