Since no one else has replied...

Take some careful measurements of both necks. The distance from the bridge to the 12th fret has to be the same with either neck installed, or the swap won't work. If the RG neck is longer to have room for 24 frets (which seems likely, yes?) then installing it in an unmodified S-type body may result in messing up the scale length. The nut would be further from the bridge, and the 12th fret would no longer be halfway between the bridge and the nut. You may find that the only way to install a 24-fret neck on your S-type guitar body would be to rout out the neck pocket to position the new neck in the correct relation to the bridge.

Whether that kind of tricky, risky work is worthwhile is entirely up to you.