I thought Johnson was an original equipment manufacturer of GM lifters at one time. I also thought they folded at one time and then the company was purchased and reopened. Hopefully someone out there knows for sure. Johnson always had a good reputation. I bought out a large inventory of parts from an oil testing facility that used Buick V6 engines and the test engines were supposed to be built from OEM parts purchased from GM's main parts distributer. Those engines used Johnson lifters.