therover87
1/2 ton status
i have an 87 k5 and i replaced the wires with msd 8.5mm, i have the msd hei coil, the cap and rotor, i have ac delco rapidfire spark plugs but for some reason my truck is running very rough at idle and it seems like there is a lack of power, there is a backfire through my exhaust as well any help would be appreciated