Sam
Don't mean to steer you away from "your" intended build in any way....but being/judging from the amount of research you have done, I'm guessing your intentions are to be as close to "movie correct" as possible. Otherwise why do all the research??
As just mentioned this could be the research thread even if you choose to go different directions throughout.. The information could be here for those who wish to proceed with the Unicorn.
I don't know how much research you have done or what documentation you already have but I literally have thousands of pics and can help you decipher "Movie Correct" vs non.
Let me Know if you need engine pics from the actual CVS car that was sold. From all my research and deductive reasoning it was either a "Top speed" car or a "Top Speed" car no other option its an auto. Most if not all the stunt cars were damaged or interior cars were all sticks along with close up beauty promo bunch.
Since your working on the engine details...Most people who are the "Movie Correct" crowd are the top speed bunch.