im kinda just learning the internals of transfer cases, i understand 4cyl gear driven transfer cases have a 21 spline input and output shafts, 3.0 v6 gear driven t/cases have 23 spline count. when doing dual cases with a v6 motor swapping a 23 spline input/output shafts into the 4cyl cases is most desired for strength. what is the 30 spline cro-moly input and out put shafts marlin is selling. is it just that...... a much bigger and stronger shafts for the 4cy cases. or am i getting 2 different parts mixed up? i have never heard of transfer cases with 30 spline shafts