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You're also correct that the transmission requires the use of a standalone computer to control the shifting and pressure. TCI offers a separate computer, software, and wiring harness package (PN 377000, $659.95 summitracing.com) that allows you to control the trans via a laptop computer. You will also need a throttle position sensor (TPS) input into the computer to indicate wide-open throttle. TCI offers the sensor and an adapter package for carbureted applications (PN 377400, $199.95 summitracing.com), but you could buy a GM TPS sensor and adapt it to your carb for much less. Other required connections include a tach signal and 12-volt power to the trans. You'll also need a specific 4L80-E converter since TH400 converters will not interchange. The 10-inch TCI StreetFighter converter (PN 242900, $399.95 summitracing.com) is a good choice, but several other companies such as Hughes and High Impact Transmissions also offer converters. TCI also makes a 4L80-E locking filler tube (PN 743805, $64.69, summitracing.com).

We also found a company called Powertrain Control Solutions that sells a standalone control computer for the 4L80-E as well as other transmissions. This ECU sells for $700 and requires a $150 wiring harness but offers intriguing opportunities such as converting to a paddle shifter control. Shiftworks also offers a four-speed auto-shifter conversion detent kit for stock shifters as well as an extension housing conversion for $495 that converts the tailshaft to a mechanical speedometer. These electronic controllers will also work for the 4L60-E and 4L65-E "electric" overdrive transmissions. For you EFI fans, BigStuff 3 offers the combination of its impressive EFI controller with a built-in transmission controller all in one black box and the price is definitely less expensive than adding a separate controller for the trans.

The 4L80-E is a monster trans that's both heavier and longer than a standard short-extension-housing TH400. It will require the transmission crossmember to be reinforced and moved rearward. There are three different-length TH400 cases and three different-length 4L80-Es, so the variations are numerous. But with this heft also comes incredible strength and durability.

'Heh, heh ... B.F.H. is cool.

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