I'm making a parts list for all the things that need or could be replaced. Truck has almost 200k on it and still runnin strong but figure couldnt hurt to do some update maintence on it. One of them being to replace all 8 injector cups. While I have the valve covers off, what else should I replace while im in there.? I was thinking new injector o-rings, cooper cush gaskets, maybe new glowpugs and stancor relay. Ford changed the cps around 100k. Anything else I could replace for cheap insurance? And is there anything important I need to know about changing injector cups like how not to lock up the engine...or how to drain the oil galleys??