I found a 1990 245 DL w/about 200k miles and B230F non-turbo that I took a cylinder head from. It failed smog in 2/05 (details unknown) but appeared to be in the junkyard due to damaged right fender and the roof having 2" dents in it (UFO landed on it?). Spark plugs were in good condiion, though they were Autolite and the gaps were between 0.035" and 0.040". On removing the head, I noted that only one headbolt had lots of dried oil throughout its shaft. This headbolt is the one closest to the right front fender/radiator. The headgasket was intact and I found no evidence of a blow headgasket. The valve cover was leaking oil, thanks to black gasket-in-a-tube. The timing belt and/or water pump have been changed, as evidenced by those items being intact but SAE bolts (between 13 and 14 mm) were present). Why did the headbolt have dried oil?