anyone do a painless wring harness?

After the many electrical gremlins I am having it seems obvious my old wiring is no longer worth messing with. I am considering just cutting it all out and redoing with a painless harness. I am seeking advice/opinions from thers who may have done the same or consider doing it. I have a 65 cuda which is mechanically all new but it is having problems being reliable starting, running, lights ect. I am frustrated as want to drive it but not reliable enough to go get groceries!