well sometimes it will run fine untell it hits 3k and others it wont, and sometimes it will kick up at about 4k im so lost with this one.. its a 200 in a 67 mustang. pextronic distrib good wires good, coils fine, just fixed a vac leak the other day but ran like a champ after then i woke up this morning and it does this to me. also it kind of feels like im pulling something when im not.