As I said in the post, the 1786 can likely be made to work. Do not use the RCA's for the rear speakers however as they are out of pre-amps (as I understand), and will not drive the rear speakers. I am currently driving the front speakers with the direct wire connect from the 1784, and it seems to work fine. I was a beginner (although I probably did twenty stereos back in the seventies and early eighties before they got all wirey, amped up, and attached through dins and harnesses). With this, I spent two hours reading every post on this cite, and another three hours with Crutchfield techs (Casey, Virgel, and RJ) trying to come to a resolution. As a beginner, I finally engineered the solution, and the experts did not have a solution. Thus, arguably, this is only a job for a beginner. Also, ignoring the learning time referenced and time scratching my head, I probably spent less than four hours with time on task. I.e., I worked for three hours wiring the left rear speaker which I tackled first, and about forty-five minutes on the right rear speaker.