I wanted to know how the obs fuel pump will be controlled. Either from integrating the obs wiring to the LS harness or from the original obs harness? I hkave already unplugged the obs pcm from behind the glove box. I have not cut that plug nor the original harness from the engine bay. Also what about the wires connected to power distribution block located on the firewall ?? What wires get disconnected? I was going to get the 12 volt power source for the LS pcm from there along with adding a fuse. I did a stand alone harness and followed the instructions from lt1swap.com .The thing is that I did not completely cut out the fuse block from the original.