wirring nightmare

[maddav23]

Need a little help with an engine swap issue. Just bought a 68 c10 stepside project but the guy before me installed a 1994 7.4L. awesome potential but now it has 2 wiring harnesses, original and the late model including computer and now has 2 gauge harnesses and 2 fuse blocks, 2 starter switches, etc,etc. It cranks and runs but I want to keep the original gauge cluster and steering column and switches and so on. Can anyone advice me on the simplest way to reconcile this dilemma? "Out with the old and in with the new" may be a good motto for the New Year but its confusing when restoring old trucks! I appreciate any wisdom.