Sea Foam saved my butt when I did my 2.7 timing chain a couple of years ago. I did my valve stem seals at the same time, and used compressed air to hold the valves up. My compressor doesn't have a trap or drier on it, so a good bit of moisture went into the cylinders while I did the work. When I went to turn the engine over by hand near the end of the job, the pistons would hit a soild wall just before TDC. Took a bit of head scratching, but i finally figured out that the carbon on the pistons and head absorbed moisture and swelled so that there was interference. I had trouble believing it, but that's the only explanation. I poured a measured amount of Sea Foam into each cylinder, let it soak for a few minutes, then used a plastic tube taped to a vacuum hose and stuck down each spark plug hole to suck out the Sea Foam and dissolved carbon - repeated 3 times. The dark black stuff going thru the hose got clearer each time. Darn if that didnt eliminate the interference.
'98 LXi - Later Concorde gages (black w/ chrome rings)/'99 LX - LHS gages (white) - HIR bulbs