ADJUSTABLE on head valve spring pressure tester for various shaft style and stud mount roller rocker systems. Great for wedge/inline motors, canted/splayed motors, and Big Chief/Spread port styles. Use it on one - use it on many. The PC-100 features four course adjustment hole locations and includes four fine adjustment shims which enable calibration to within .050" of rocker arm pivot length. Just unscrew the handle and move the load cell module in or out for proper length across the rocker. This LSM tool comes equipped with a 0-600 lb liquid filled gauge and an 8" long handle. Comes standard with new and improved billet steel rocker hook (HK-003), and includes set-up and adjustment guide. A high quality, precision tester made in the USA!