Any guesses as to what engine this intake fits?

honestly, i couldn't say.

the air temp sensor leads me to think that maybe it was setup for some type of forced induction which used a blow thru carb, i'd guess? maybe?

i do know that aftermarket intakes for those are insanely expensive (or were at the time) so a homebrew piece for all out performance would make sense.
When it was i.d.ed as a 4.6 four cam, forced induction is the first thing I thought of, considering the fabbed top.
And I think the little v6 contour svt used a similar idea, 12 intake ports.