B rad, what I think you have is the Railking IMPERIAL version, which I believe came from the older earlier MTH Premiere tooling. For a while MTH was putting these in starter sets before they went back to the originally tooled Railking version. While that IMPERAIL version did negotiate the 031 curves of the track in those starter sets, it looked pretty ridiculous doing so, IMHO.
By the way, I had one of the early version MTH Railking Dash 8 diesels and was running it on 027 curves with no problems. Though I personally thought it was a bit large (boxy in proportions) for even a traditional engine. The Railking SD90MAC was the best selectively compressed of all the larger prototype engines that MTH bought out in their early Railking lineup.
Just to confuse things a little more, some of those original Railking diesels got moved to the "Rugged Rails" line up before MTH eventually dropped that line.
The tooling Lionel purchased was for the earlier Railking (Rugged Rails) Dash 8, which is around 14-1/2 inches long. The copy in the Lionel catalog is obviously wrong, listing it at 10-1/2 inches in length.
One never knows these days what to expect from new Lionel products. The MTH version had larger vertically mounted can motors, similar in design to the way the LionChief Plus diesels are. BUT will Lionel spend additional money to retool the trucks? It'd be better for them to use the tried and tested truck mounted motor as with many of their other LionChief diesels.
My guess is they'll go the design route they went with the starter set Tier 4, with the same undersized motor. A mistake in my opinion, but actually I think the whole Tier 4 design is a giant goof. At 17 plus inches in length, that ain't no traditionally sized diesel. But that's what happens when you put scale guys in charge of designing a new traditionally sized product.
Seeing the goof up of the Lionel Tier 4 diesel makes me appreciate the work and effort that went into designing the earlier MTH Railking diesels. And of course, the postwar thru MPC Lionel products. There is a fine art to selective compression, which Lionel didn't even try to attain with the Tier 4.