I've had a 273 all my life. Evidently you don't know much. Passengers have freaked at how fast my Barracudas were, and I was driving normal for me. They were daily drivers, not trailered, ever. And just for the record, I have an original 68 Fastback Barracuda with a 383 and a 2009 Challenger 6 speed R/T. All three are fast. I also had a 71 Duster 340 4 speed, just in case you think I don't know what is fast... Keep playing the numbers game instead of building and driving something. If you can't make any MOPAR engine fast, and I'm including slant sixes, you don't know what you are doing.