They are the same thing....
MIL= Malfunction Indicator Lamp (the proper dcx term)
CEL= Check Engine Light (general shop term for all brands)

MP wanted to make it easy as possible for guys with older cars to install the crate motor, so they stripped the PCM down to the bare essentials to make it run in that application, and made it 100% simpler than the production wiring/computer. Open loop/no
02 sensors at all. Pretty much all your sensor readings are on the intake side + temperature related stuff. Must use a hydraulic shifted trans, also.

Also earlier there was a comment from somebody above who believed the 2 crate engine intake manifolds might be the same....they are machined differently so I guess that'd mean they aren't the same. The EFI manifold is machined for injectors wheras the carb manifold is not...not to argue or be contrary, just fyi/general info.