“Old high mile Hellcat”…. Did you miss the 44K mile part?
44k miles on a 15-16 Hellcat s both old and high (7-8 years old on a FI engine is a long time). One does not simply buy a blown V8 without getting it fully inspected, to include a leakdown test. More than likely, you don't know if that was 44k miles driving across the state of Iowa every week, or if it was a mix of driving with several hundred passes done at the drag strip. Hence why high mile 15-16 HCs are cheap, relatively speaking. They have the least amount of factory improvements and some known weaknesses. This is especially true if they started life as a lease vehicle, as those were often abused and were returned with a lot of miles on them.
This is why it is absolutely imperative that used HC buyers pay an independent specialist to fully evaluate the car prior to purchase. These are not Mustangs or Camaros. If you blow the motor, you're out a new Toyota in terms of engine repair costs. Spend $200-$300 and get it inspected to within an inch of its life. $300 today is a lot cheaper than $20 grand tomorrow.
They weren't Hellcats, but the blown V8s I've built for myself over the years were rebuilt between 30k and 50k miles. As soon as they started showing compression loss, off with the heads.