new to site and obs trucks need help!

hey everyone, i am new to the whole truck scene,but i would much apperciate the help. I have a 94 that i am doing a lsx 6speed swap in and need wiring help. I am very mechanicaly and electricly inclined so im not new to working on vehicles. I have put the harness on the motor and have pulled the stock harness for the most part. unfortuneatly i have to use the fuse block off the truck for the lsx harness. whats the best way to aproach this, do i need to take the whole harness out of the engine bay or do i just strip the harness down to everything but the engine controls and go from there?

im pretty sure that you have to have a complete LSx engine harness for everything to work, the OBS harness wont work.