I did. I took my 13.5:1 451 out and put in a 9:5:1 383. I went from 9.80 to 11.20. I put carpet in it, bench seat, a little bit of exhaust and a set of torque thrusts with drag radials. Being able to put pump gas in it is very nice. It is an around town car at best, I still have the 4.56's in it, but I do have a spool and 4:11 sitting under the bench. It lets me go get ice cream plus allows me to run a low key Saturday night program at Beech Bend, which I like a lot. I am using the car more than I was and it is allowing me to hone my mechanic and race skills, without as much time commitment. I will say though, the 451 is in the corner and I just bought a new (bigger) cam for it, so at some point I do plan to fast again--just hoping it is more in a (63-65 post b body) Nostalgia Super Stock format.