Any monkey that's halfway decent on a lathe can make the pucks pretty fast, getting the alignment bar can be tricky, if you have an industrial scrap-yard near by, you mite be able to find a very long hydraulic ram to rob a shaft out of, they make perfect alignment bars, if you can find the right one.
I think I'll find a lathe I can use and make my own. $525 is a bit steep for how often I use it.
That's a good idea on the ram. I was just going to buy a thick wall piece of DOM. 60" is way too long. It only needs to be long enough to reach the farthest bearing on the center section. Maybe 40-45" for a wide off road housing.
Just looked at the Mittler Bros. narrowing kit and they are using turned, ground, and polished bar stock (TG&P) which you can buy direct from the metal suppliers so there is no need to do any machine work on it after it comes in. . .we use TG&P occasionally here at our shop when we have nominal dimensions that don't have tolerances tighter than +/-0.005".
For an 1 1/2" x 60" piece of 4140 TG&P (heat treated to and guaranteed to +0.000"/-0.001") it costs about $93 not including shipping and handling. . .so are the little pucks that Mittler sells you worth $400 additional dollars. . .guess it depends on how often you are going to use it and what type of machining/machinist you have at your disposal.
Plus the additional cost of the TG&P is minimal over the cost of 0.250" wall tubing. . .the last batch of 0.250" wall tubing I bought cost about $15/ft. . .the price I found for the TG&P is $18/ft. . .it's expensive, but it's ready to go. . .as soon as it shows up on your doorstep.