Review on Boost Engine Performance with Big-Sert OverSized Spark Plug Kit M14x1.25 p/n 5141S by Jorge Kehayas

I was really skeptical about repairing a previously repaired whole spark plug. I seriously considered taking the head out, repairing and restoring it. I'm glad I decided to buy the Big Cert kit instead. This is a very high quality set with clear instructions. The entire process took less than an hour including replacing all the spark plugs and cleaning. I was really impressed with the solution. Good product! Kind of wish I had more whole ones to fix.