I have a 1970 Challenger T/A, all stock, all numbers matching, 78k original miles. To my knowledge, aside from a clutch and regular maintenance, there has been no engine work ever. The engine starts easily and runs strong, there is no smoke, spark plugs show no oil fouling. There is some lifter noise occasionally, not bad, but consistently on lift-off and other conditions where oil pressure decreases, minimal or no noise at cruise. Oil pressure is good overall, viscosity is correct and the oil is fresh. No lifter noise at idle. I've reset the lifter pre-load, there are no bent pushrods and no visible damage to the rocker arms. This is probably just lifter wear, looking for more experienced opinions that mine on if it is worth it or not to replace the lifters without touching the cam, timing chain, etc. Not a difficult job, but looking for opinions the value of doing it now, or waiting till i go through the entire engine.