Ok guys, well I finally got enough time to thank all of you folks for your good and useful advice.
The engine had about 80,000 mile on it after a rebuild by a reputable engine rebuilding company.
It had been clicking for quite a while and I couldn’t find time to check it out , just knew it was something to do with the lifters, so just drove the heck out of it, then the back cylinder went completely dead. Lifter collapsed from wear on the cam end of the lifter, cam lobe was almost completely round. So during the cleaning process I found a chunk of something in the oil passage that oils that end of the cam. I replaced cam, cam bearings, all lifters, one push rod, timing chain, crank shaft gear and cam gear. All of this gave me the opportunity to pull the pan and clean most of the oil contact area, was amazed at how much gunk that was caked on everything. Wonder what kind of oil the previous owner used. There was no wear in the cylinder walls so that was one good thing
All is well now and again thanks a lot to a great bunch of guys