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Hi everyone. Used to work on muscle cars back in the 60's and 70's. Had a C3 Corvette in 1985. Gave it to my daughter in 1986. She kept it garaged and gave it back to me for my 70th birthday. Old 82 motor didn't even rate 200 hp. Son talked me into doing an LS3 swap. Been working on getting the C3 going for 22 months. Much of my swap time is spent doing research. Had lots of trouble and learned a lot fitting the 4L65e transmission, the Corvette water pump, the hydro brake booster, the vacuum system of the old car, the wheel off set, and the car is still not running. My lack of experience has driven the cost of R & D way up. This Forum has saved me much pain. Still have long way to go. Present problem is finding out what the lever on the 4L65e does. Don't have the TCU installed and the 4L65e has all of the stops the old 700r4 had - Park, Reverse, Neutral, Drive, 3rd, 2nd. Without TCU all I have is reverse and 3rd gear. What are the 3rd and 2nd gear stops on transmission for?
Any help will be appreciated. Have had sleepless nights thinking I have taken on more than I can handle. Have learned a lot and will be glad to share. Thanking everyone for all of the help I've already received from the forum.
There should be a black plastic "position resolver" on the side of the transmission.
It has a electrical plug that plugs into the rear of the resolver. although you can pick gears the analog sifter only manually selects park, reverse and drive. The electronics do all the shifting. The reason you have third is that is the default setting of the transmission if all the power is removed. Designed to get you home or to the repair shop only.
What is the engine and transmission out of? A 4l60e has all the detents that older transmissions have, park, reverse, neutral, overdrive, 3,2, and 1. The 4l65e is the same trans just beefed up a bit inside. So you should be able to hook it up exactly as your 700r4 was, and it should function exactly the same as well. Not having power to the trans will cause it to default to 3rd gear, and although I dont think it will necessarily harm the transmission, you certainly dont want to run it this way very long. Also you say you dont have the TCU hooked up, but 4l60e's are generally run off the PCM, as I dont believe they came factory behind an LS3. A 6l80 would have a separate TCU, and is what you normally expect to find behind the newer engines.
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Having 4L65e problems doing LS3 swap 
