Hello, I was wondering what the difference between a 2002 and 2003 4L60E is. I have a built transmission in my 2002 and am in the process of putting it in my 2003 truck. Well I thought they were identical until I noticed fluid in the middle of the round trans connector, so I went online to buy a new internal harness and found that they have two different internal harnesses at 2 different prices. $40 VS $90. Which internal harness should I order and will the trans work in the truck? Is it a matter of changing the tune in the ECU?