Revision as of 09:15, 20 June 2014
FS5R30A is the heavy duty Nissan gearbox used by RB26, RB25DET and Skyline 4WD applications. It is stronger and heavier than the FS5W71C used by RB25DE smaller engines.
30-series are common upgrades for applications over about 250rwkw when you really need to upgrade from a 71C for reliability.