r33 box yea stronger! but! ya need a propshaft! ya need messing about with speedo etc good upgrade for a drift car but road car wouldnt bother! as mick said there pretty much the same as a SR20 n there are plenty of big power sr20 running with standard boxs! rb20 wont be a prob ! plus rb20 box are cheap so why bother,

Id spend the moeny else where