Actually, the latest version is a 140 (#124 500 04 06). The cap number is a multiplicative, refering to the pressure at which the cap will open to blow off excess system pressure: the "100" cap opens at one atmosphere; the "120" cap, at 1.2 atm; and the "140", at 1.4 atm. These later caps permit engine cooling systems to run at higher pressures, thereby elevating the boiling point of the coolant.