I have an 85 lx that i used a complete harness from an 89 speed 5.0 donor car. By complete I mean from bumper to bumper. I did this way back in the 90's. I now would like to put the original 85 2.3 lx 4-cyl, with a/c, dash back in. How complicated would it be to integrate it into the 89 harness? Where besides the chilton manual diagrams could I find better wiring diagrams?