83 Crew cab lq4/4l65e/4484 question.

alright i have an 83 1 ton chevy crew cab im putting an lq4 with 4l65e and a 4484 transfer case this setup came to me via 2004 h2 hummer that was getting a duramax conversion anyhow i have gotten a stand alone harness made got my dbw pedal and tac module i am wondering how i am going to get my transfer case into gear now if i buy the push button 4x4 out of a newer model truck do i need a transfer case control module? or can i just wire it so i can send power to the motor to lock it into 4 low 4 high 2 high neutral? also how am i going to achieve a speedo cable haven't seen anyone listing a manual speedo tailshaft conversion this is pretty much the only 2 thoughts keeping me from doing my conversion hopefully you all can shine a light on the subject before i lose hope and go buy an old 12 valve cummins and put into it anyhow thank you for any input.