Pretty simple-
Coming from an Ex-lincoln guy, 87-92 LSC's are indeed 5.0L H.O. roller motors (225HP 300lb-TQ). they have speed density set-ups though, not mass air. Never was mass air, Although can be set up as one.
You must be careful, because Mark Vii bill blass models are not the H.O. motor. Easy way to tell-Digital dash cars always came with non-H.O.'s. Analog gauges were H.O.'s. They have the non H.O. set up. As the CONTI's and Town cars are all non h.O. versions of the 5L. Lincoln's LSC's were billed as the gentlemans mustang in the 80's 90's. And always look under the intake plaque for the inscription H.O. on the plenum.
Also know- the injectors are 19lb'ers, the intake tube is smaller and isnt the mustang intake tube, and the bracketry for the accessories are different as well. The smog crap and everything else is identical to the stang, except the pullies ar4e larger on the lincoln too!
hope this helps to clarify!
Anthony