I have an '87 302 with about 140k on it. It's been running like a dream for 4 years, suddenly the motor started choking like a single cylinder misfire and ticking loudly from one valve cover. When I start it cold it runs very smooth, but after it warms up I get these symptoms. It sound like a bad lifter, rocker, or a bad valve. Can anybody explain why it only does this at operating tempurature?

For now, I just want to replace the worn components. If I have to replace the cam (depending on...

'87 5.0 Lifter ticking and misfiring when hot