TOMEI VALVE SPRING SHEET RB 0.5mm SET 12pcs For NISSAN RB26 RB25 RB20 162003Brand TOMEI Product Number 162003 Compatible Car NISSAN Compatible Engine RB26 RB25 RB20 Product Description APPLICATION & PURPOSE When installing aftermarket valve springs in a head assembly, the amount of load applied to each spring need to be adjusted until everything is in uniform specification. This is a standard procedure which all race engines go through in order to be able to raise the engine RPM without any glitches or hesitation. The