Yes many times with two different hyper spark distributors. The plastic cap works and it is the easiest one of the Holley distributors to set up but the motor still had the same reaction to it so I am thinking about tearing apart this motor I feel like it’s somehow related to the Cam I cannot figure out how the cam could be hurt with all the other things being good. but I’m tired of it. so besides the damper being junk I’m going to tear it apart. The bumber will be when I tear it all apart and I can’t find anything wrong with it that will be hard to swallow. I am going to the Nats in a couple weeks and I will be looking at stroker kits there and talking to builders I will be selling parts in the swap meet area also