I had my 289 rebuilt a second time By professional shop. 1000 miles on first rebuild new oil pump, aluminum heads, lifters and intake installed. After 1000 miles I did use break in oil, a knock developed on #7 cylinder, the first 950 miles developed a slight tick when warm the final 15 miles it became a knock. Pulled engine. The engine rebuilder found #7 crank bearing damaged. Found metal fragments, crank damaged and could not be turned a second time. Engine dissembled completely flushed engine, lifters block etc. new crank, honed cylinder walls and bearings installed. This time I had the engine builder assemble a long block. Started engine with Edlebrock lifters reinstalled in correct location. Starter engine after oil priming engine through the distributor shaft fo 15 minutes with electric drill With break in oil. Ran engine like new break in For 25-30 minutes at 2200-2500 rpm. At first start up lifter I believe #7 exhaust noisy was quiet after 5-10 seconds. Engine up to temp lifter started clicking. Tried to adjust, no results. Checked exhaust manifold bolts all torqued to specs. Tried adjust #7 while running, could not take noise out, using cut valve covers. Lifter is bad. Can I replace one lifter without destroying the cam. At this point I have nothing to loose except $. It is the original A code bock which was rebuilt in the 80s. Can I replace one lifter that is bad. Very frustrated. Could the block have an issue with oil flow? Help!