So this past weekend I bought a 93 6.5 dually with a bad transmission (fluid pump went out). I have a 4l80e sitting in my garage out of a 99 vortec truck 2500 so figured what the heck and stabbed her in this morning. I put the diesel converter in it) and when I went for a test drive the trans felt solid as a rock but will not shift threw the gears in any way at all not automatically nor manually. Any guidance would be greatly appreciated. Thank you.