Is it worth taking the time to port match this intake plenum to my SC? Also is the back of the mp2 supposed to be this wide already? ( Bigger than the mp Plenum )
If you are careful to maintain proper radius and make sure that you aren't making a reverse funnel, it can be helpful, but mostly it's not a big deal because the plenum itself only flows about 700cfm whereas the blower is capable of more. Of course this is all a function of boost and OD levels as well. Maxing out pre-blower flow is only important if you can keep the blower at a reasonable boost level while achieving high volume airflow.
Case in point Kevin Leitem ran an off the shelf S-port blower into the low 11's back in 2004. The S-port had the stock 94 sized inlet.