No offense Johnny but I bought one of those Professional Products harmonic balancers and it wound up costing mr $12,000. I installed one on my supercharged 340 that I built in 1988 (about 30 years ago) and I should have known when it just slid on my crankshaft without any effort. Well after it was on for a few months I stopped at a gas station to fill up the Dart. After filling up I started the car up and heard this horrendous knocking that sounded for all the world like a rod knock. I limped the Dart back home and the next day I got my buddy Larry's opinion on it . Larry was in agreement that it sounded like a rod knock so I started the wheels in motion to build a new engine. It was when I was disassembling the engine that I discovered that the the balancer had come loose and THAT was the cause of the knocking and it also tore up my timing cover on the process. When I built this engine I installed a Summit brand degreed balancer and it fit like they should (had to be pressed on. Just a heads up. Also even though I love the performance of my new 418 striker (490 horsepower and 516 ft pounds of torque) I might have been better off with the Blueprint Engines stroker as I have a oil leak (either rear main, camshaft plug or one of the two oil galley plugs) and it's coming out of the bell housing. Also I am building crankcase pressure and its pushing the dipstick out (might be why the main is leakin). I did a leakdown (the engine was cold and the cylinders were dry) but the cylinders varied fro a low of 3% to a high of 16%. Some have said that I need to not baby the engine but give it some full throttle blasts (dangerous with my tires LOL) and also gear down when coming to a stop, we'll see. Anyways this is where the BPE warranty comes in, maybe next time.