I have tried to research this but have found conflicting answers. I have a 1986 XJ Series 3 Engine that I am putting in my project. The cams have the same numbers on them, P31818A and LYD 4. I might add that I have had them reground. One cam has a threaded female end, which I was planning on using for a rev counter. It looks as if this would fit better on exhaust side as the rev counter’s seal and make up seem to fit better with the relief that is on that side of the head. The other Cam has no threads and no plug, which leads me to the question, does it need a plug? I have had this motor together but had problems getting it running well. So I took the head off and am starting over. I am learning on the go. I am wondering if the cams were in the wrong position before I took the head off?
I appreciate any feedback.
Thank you in Advance!