The Monte Carlo is a better bet financially since they're cheap all over the country. If you buy something cheap, it's pretty much not going to depreciate. Any work you do to the Monte is going to raise its value, not the case with a '96 Cobra.

Working an '85 Monte SS is easier than working a '96 Cobra. In '85, engines still went into the car from the top, not the bottom, so it'd be easy to yank that weak ass 305 and stick something in there. It's possible to get a big block in a Monte SS, I don't think it's as easy in a '96 Cobra. Also, '85 means it's 20 years old and a lot of emissions laws (if ever brought back) would not apply.

Insurance is probably cheaper on an '85 Monte Carlo. Chevrolet parts are usually cheaper than Ford parts too, at least from my experience. Plus, an '85 Monte Carlo is god damn comfortable to sit in. I don't fit in new-model Mustangs.