Do you still have your seat presence safety? That one kills the engine. The others keep you from starting, IIRC.
As for the interesting problem with the balance shafts, I suspect not only the crankshaft does not swap with the non-shaft version, possibly the pistons don't either. I have rebuilt 4 of the 3-cyl versions of this engine (3TNE84), and the pistons have steel weights cast into their undersides. No balance shafts.