Non OEM engines happened more that you might think. I personally know of a 70? 340 Challenger and a 71 340 RR The Challenger had a twisted axle and a rod sticking out of the block. The RR had a 318 transplanted to replace the 340, I know because I drove it.. BUT this was back in the early 70's when they would get repo by Chrysler Credit
I had a 69 Dart Western Sport with the leaning tower 6.. Wish I still had it....