to me it sounded like a miss, it increased with the speed of the engine, but as i am sure everyone here has noticed i dont know all that much... so i am not 100% sure what it is (or i would have fixed it,

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the fuel filter is only a few months old, and from my experience with fuel filters, its usually the other way around, runs bad at idle, but better at speed.
my battery has been having problems lately, gauge shows volts at or below 13, Alt is new.. i was going to change my ground coming off the battery and see if that helped the low voltage problem. This has been going on for some time, but the stubbling problem just started today. Could the weak battery have messed up the HEI? now that i think about it, it sounds like maybe something in my distributor may be messed up. advance weights or something... will check that.. any other ideas?