Take a look at the link below where you can put in different years/engine combinations and what comes up as the induction.
By what I can tell, mpi as we know it now for the 454/7.4 came out in 98.
From 94 through 97, it seems they use the 'mpi' letters but really those years seem to show it as "efi" in the diagrams.
93 and earlier show having a carb.
