454Mag repower ECM compatability

[ScryD]

Hey guys, I have a 96 regal Ventura 8.3 27' just pulled the merc 454mpi (330hp) and I am doing a repower with a 454 Mag longblock. I know for max performance I should find a complete HO intake and setup. But for now Im going to run the old MPI intake on it due to $$. Question is: will the mapping on the ECM from the MPI be enough to run on the Mag longblock given the cam differences? I know im robbing my self of power but last thing I want to do is run lean and burn these rec-port heads. My .02 is that displacement hasnt changed, only cam and flow ability. (which will still be restricted with intake and risers)
This is my first time messing with Merc inboard electronics so Im lost.
Thanks

 

[scoflaw]

Will that intake even cover the rec-port openings ?

 

[ScryD]

yes I just have to use the mpi gaskets

 

[Scott Danforth]

you cant run oval port intake on rectangular port heads with factory MPI.... the MAP signal back to the ECU gets screwed up. while it will run.... it wont run well.

plenty of MPI parts on ebay cheap....

 

[ScryD]

Where would these intakes receive a map signal from? there are no o2 sensors?
I thought these were closed loop systems?

 

[Scott Danforth]

the MAP sensor on the intake

these are basically open loop speed density (reading TPS, ECT and MAP)