Why - Having done a couple V8 conversion 1 in a 60 and 1 in a 40 its not cheap to do it right on a vehicle when nothing else is need, not the case with the 83. Did you miss the interior? The 85 is a POS and will never be nice unless you have stupid money and a ton of time.
That’s kind of how I look at these, non operating and a POS= parts truck. Mostly original and runs good but looks like hell or looks good and mostly original but inoperative, either one I could live with bringing back To life.