My point is that the prefix does not define the engine by the vehicle it came out of, or even to the point where it is useful.
Incidentally, I wasn't aware that the Samurai's came with MPI - in fact I just took a look at the parts listings and up to '95, which seems to be the last year it was sold in the US, there is no MPI shown, only carburettors and TBI, I was also under the impression that Samurais came with the G13A (cast into the block - not just a prefix), the 1324cc engine.
However for the sake of discussion, let us assume that you have an MPI 8V, SOHC, G13B engined Samurai - should we assume that the same computer that runs my 16v, DOHC G13B, will also run your 8v, SOHC G13B, and where does my other G13B (the 8v, SOHC one) fit, it's never had a computer?