I've about had it with this truck but stuck with it for the moment. I've had a constant Misfire on #3 for about a year and a half. I've replaced the plugs, coil, wires, distributor cap/rotor, intake plenum gasket and lifters trying to get it fixed. There isn't any abnormal pressures during a pressure test and hold the pressures fine (no leak down). It is intermittent but for about 2 weeks at a time (two weeks on and then 2 weeks off) and this misfire only occurs at idle. Higher RPM's make the misfire go away (oil pressure around 42psi).