MAD electrical upgrade modification?

Lookup "fleet bypass", which is what you are doing. Chrysler did that on taxis and police cars. In my 1964, I changed to a 1965 bulkhead because it has thick buss-bars for those wires. Won't work in 1966+ cars due to the wiper adding a 3rd connector. A bullet connector might be better for high amps than a spade. Bolted connections are even better. My M-B cars have small covered screw blocks next to the battery. I put them in my Mopars underhood to branch the IGN circuit. They are 3 screws, but 2 are connected to the same copper block. Easy grab at PickNPull.