In the name of God, and peace and blessings be upon the Messenger of God.. I have a four-speed Caprice gearbox with an internal Transgo modification. I just bought the car and it has an electrical problem. I wanted to change the gearbox to a 6-speed with the complete wiring harness because of the wiring harness problem. According to the owner, the gearbox is clean and the sale will be easy, God willing. Four speeds