Can you change just the lifters in a engine or do you have to replace whole rngine?

You can change just the lifters in an engine without replacing the entire engine, provided that the rest of the engine is in good condition. However, the process can be complex and labor-intensive, requiring disassembly of parts like the cylinder heads. It's important to address any underlying issues that may have caused lifter failure, such as oil flow problems or wear, to ensure the longevity of the engine. Always consult a professional mechanic for a thorough evaluation.