[bullseyeprec]

I went to the dyno last week and got a high rpm miss. I dyno'd at different total advances, 32, 34, 36, and 38 and made most power at 32 degrees total. I am running a 392 crate motor with a duraspark dist and a msd 6al. Problem is I start missing at 4200. We swapped rev limiter chips 3 times and checked cap, rotor, plugs, and cap. Seperated plug wires and replaced coil. no change. We swwapped power valves and jetts to get 12:1 air fuel ratio but miss is still there. The dyno guy says its spark for sure since his equip reads spark discharge I just dont know whats wrong. He siad he doubts the msd is bad. I am not using the vacuume advance. Today I pulled the cap again, pulled the rotor, pulled the plate the cap screws to and looked at the plate that would rotate if the vacumme advance was hooked up. It rotates in a circular fashion as one would expect under diaphram resistance...BUT, It also wil lift up and down. There doesnt seem to be anything holding it down. Also, there doesnt seem to be anything to limit up and down travel so it doesnt look like anything is broken? Is that a problem? If not, any ideas? I sure appreciate your input. By the way..I dynoed 339 HP and 360 torque at about 4200.