Building a More+AC0-Durable Street 700+AC0-R4 Overdrive Automatic

The world is full of compromises. What we’d really like to run in our next Chevelle Pro Touring project is a GM eight-speed automatic with a paddle shifter behind a killer all-aluminum 427 LS engine cranking 700 normally aspirated horsepower. That’s what we’d really like to do.

But the harsh reality of life points to a powertrain that must be a bit more conservative that includes a carbureted small-block Chevy and a basic, 30-spline, 700-R4 four-speed automatic. The overdrive trans promised decent street performance after a freshening but we were hesitant to employ it after witnessing a string of poor experiences with TV cable snafus on two different friends’ cars.

That’s when our auto trans builder Jimmy Galante of RaceTrans in Sun Valley, California, suggested that he’d had great luck with converting a 700-R4 to use TCI’s constant pressure valvebody on street-driven