15 16 17 18 19 20 21 gearbox tech info the mark 4-9 hewland and webster gearboxes ... are quite rugged for their size if properly set up the unit should ... trouble free when used with a ff1600 these gearboxes also perform well in s2000 ... service but because of the extra torque generated by the 2000 ... engine some extra care is necessary since the gearbox does not ... bolt directly to the engine but to an adaptor which attaches ... to the engine a spacer or bobbin is used to correctly space the clutch ... bearing most cars use a standard bellhousing adaptor which is 2.15 thick some cars ... use special bellhousing adaptors which are thicker and thus a ... long input shaft and long bobbin is required racing type f-3 clutches will ... spring height differences we offer these f3 type bobbins in the proper lengths ...