If I remember correctly that is the year that the 211 S/C E started. If so we are talking about the same M113 but there is alot more to it than that. I would find another N/A M113 to use. This way you don't have to mess with electronics.
First thing is that I've been told the M113 from the 211 cars has a more robust bottom end due to the S/C being factory installed. This is a good thing as it makes for a stronger motor. However, is the CR gonna be the same? Will the E55K motor accept the intake manifold from an N/A car? Are the heads the same? Remember, the E55K motors have the supercharger mounted on top with the coolers where your current motor has it's intake mani. So even though the bottom end is essentually the same I think there are many little details that would not be worth working around when you can get a N/A 5.5 and use it as a true plug and play.
If you are considering swapping the 55K motor and keeping the factory SC your in for alot of work and headache.......
Lastly, if anyone does know about the E55K "bottom end only" being swappable into the previous M113 cars I would love to know. I've gotten very "ahh not sure" answers on this. A 5.5L with beefed up internals is exactly what my car needs.
....If I were you I would wait around for an N/A 55 from the E or S.