Matt, I'm a big 027 operator and had a several dummy K-Line Alco FA's along with several Lionel MPC era dummy A and B Alco units. The K-Line dummy units use the same basic truck assembly that is used on the motorized units.
But the Lionel MPC-era dummy Alcos use a separate style dummy truck that is much more free rolling than the K-Line ones. But the truck mounting pins/holes are in different places.
So I've been using thick black styrene to create new dummy frames, and drill truck mounting holes to match up for the Lionel MPC dummy trucks and also holes to match mounting of the shell. You could use basswood or plywood too. But I got a deal on a bunch of thick black styrene that I bought for the intention of making frames for dummy units.
Maybe you already have some MPC dummy units. They're certainly not all that expensive on the various auction sites and probably cheaper than buying the trucks through a parts dealers, though I seem to remember seeing them on Jeff Kane's parts lists.
Anyways, just an idea for you. The Lionel MPC era dummy trucks cause far less drag than do the K-Line ones and allow a longer train with less stress on the motorized unit. You might be able to use dummy trucks from other manufacturers like MTH. It's just the Lionel MPC ones are far more common and I would gander less expensive and would probably suit your possible project much better.
AS a PS, I've even made a new frame to replace the metal one of one the newer Lionel LTI era 44-ton switchers so that it doesn't ride so high. I was only able to lower it about 1/8 inch but it still looks better than before.