Sure, but unless you've developed a superconducting substrate, or come up with a reliable, efficient 3D cooling system, or are willing to run the 3D transistors only at very low speed/power, you're going to run into serious heat dissipation problems.
Back then I was proposing a diamond semiconductor - supported and powered by water-cooled silver busbars. Diamond is extremely conductive thermally. The bandgap is 5.5V, corresponding to the deep ultraviolet, so you can run it very hot without fouling the electrical properties (though you have to keep; it below 752 F or it will gradually degrade.) I'd want to put it in a bottle with an inert atmosphere so it wouldn't oxidize at high temperature, either.
The flip side of the big bandgap is that it consumes more energy - and generates more heat - when switching than current silicon designs which run at about a third that voltage.
These days I'd probably go for layers of graphine, which conducts heat even better than diamond.
With a rectangular solid you can get a LOT of transistors (and their interconnects) into a few cubic feet. The original proposal was for a six-foot cube - 216 cubic feet. Powering and cooling on two faces gives you 72 square feet of heat and power transfer serice, with 432 square feet on the other two faces for optical I/O fibers. Nowadays I'd take a page from Gene Amdahl and go a tad smaller: so, like the 1960s-era cabinets for IBM compter components, the block of logic and its supporting structures would fit into a standard elevator.