Transfer case input interchangable???

Ok, my '88 Wag Limited has a np242 Full time case....I've got a np208 out of a fullsize cherokee, with driverside out put and and a rear fixed yoke.

My question is that my np208 is a 23 spline input and my 242 is a 21? spline input, if I took both cases apart is it possible to put the 242 input into the 208 case so that it will mate to my current aw4? If not, is there another 21 spline input the correct size to install iinto the 208?

Thanks,
Justin

anyone?? (bump)