low rpm miss when get on gas

[lib88stang]

I have had a miss now for awhile. I recently had a high rpm miss at 4k rpms, but I put an MSD 6AL and it went away. Now I have a miss between2k and 3500k rpms. Usually when I'm pulling a hill or getting into the gas. I have a fuel press. gauge i can watch and it doesn't drop when it misses. Also it doesn't do it all the time, it will miss then it will go away and run great, then it will miss again.

I replaced many parts, any help is appreciated. Thanks