Right now the 68ltd is being really, really ghetto.i drove it around town for a few miles and it started bogging down and getting no spark. it broke down and i got a ride back to my other car and i went and got a new set of points, rotor, condenser, and cap. after i replaced that, it started, but every time you revved it, the intake would backfire like mad. i don't know what to do with it, timing is really weird on it. you advance it, intake backfire/you retard it, sluggish and intake backfire. i wired the cap the way the manual says for a 390 4v, i'm starting to think that its wrong. if information is what you need, it's a Z engine code, and U tranny code. it don't have the other info with me right now because the car is broken down in a parking lot. thank you alot if you can help me at all. i want to get this thing to go like a beast again.