If I had to stuff a different engine into a Prius, I'd probably go with a built 2ZZ-GE out of the Corolla XRS or Lotus Exige. There was a blown variant Toyota built for Lotus. Hellcat motor will be ahem, a tight squeeze into one. Hayabusa motor has been done. I think an older K-Car or even the 1st-2nd gen Chrysler minivans would be a hoot with a Hellcat under the hood.
I get why someone wants to swap in the K20 Turbo CTR motor into a older Civic, as ricey as the 1990s Civics got, they handled quite well for a compact car - light and one of the few mass-market cars(excluding Ferrari/Porsche and Honda's own NSX) besides the Lexus LS400 and the Mercedes W140 S-Class that used double-wishbone suspension front and back. Honda was really proud of that fact but switched over to MacPherson struts across the board in the 2000s.
I remember, fondly, from my days at the track there was an even older vintage Civic with a newer engine swapped into it and a huge honkin' turbo on it. Thing was running low 13's IIRC and they had the valve cover off and a breaker bar on the head bolts between runs trying to get the head gasket to stop leaking hahahahah.
Back in around 2004 when I was working at US41 Dragway, I had the privilege of seeing some of Precision Turbo's cars TNT on closed-track weekdays. Harry was a track sponsor, and so they had carte blanche access to the track. One of my mind-blowing moments was seeing the late Stephanie Eggum's Civic that had a K16 with a 74mm turbo, and made over 1000HP. It only ran around 138-140 in the 1/8 mile, but trapped in the mid-180s in the 1/4 (I know because I ran the clocks for these trial days). The most humorous thing was when Stephanie would get in the water box a little crooked, Harry and the team wrench would simply walk over, grab one side of the wheelie bars, and lift the back end up and move it over to get her straight!!!
