Your best Mopar deal

Would be my first dealer purchase.
In '73 I bought a '66 Sport Fury 383 4bbl auto on the floor, counsel, buckets, power steering, power brakes, midnight blue(?). 200 out the door. The dealer said it was knocking. Although quiet and steady at idle he showed me how he could hold the brake in drive and bring the rpms up then the thing would start knocking. Everything on the car looked great except for a small spot of rust over the right rear wheel. A friend assured me he had a running 383 in a parts car for 40 bucks. So I bought the car and the 383. Guys at the HS Auto Shop commented how smooth this car would idle and were surprised to hear the knock.
So we go to swap the engine (my first time) at the machine shop I was working at on a Saturday morning. Got all the hoses, coolant, exhaust, and other engine stuff ready and my friend got underneath to the trans. Starter, and converter inspection cover was removed.
He comes up asking why the hell we're doing this.
Engine knock I replied.
He says, "You have a loose flex plate bolt on the converter".
Evidently it was slapping under load and increased rpm. Nothing wrong with that engine.
Learned a bunch that day