Seems like today the debate between going with a stick or an auto in a classic Chevy is more heated than ever. With the advent of better electronics, mechanical innovations, and the natural progression of technology, we have paddle shifters, push button shifters—a variety of ways to shift an auto trans manually—without having that third pedal to exercise our left legs.
With the goal of our '67 Chevelle being a real world street car that we could enjoy numerous ways (autocross, drag strip, long hauling, local street cruise, etc.), choosing the right transmission was critical, especially when considering that our rebuilt 402 big-block is going to be putting out in excess of 400 hp to start with, and grow from there. Combined with the 3.73 gears recently installed in the car's 12-bolt, something with a good overdrive was definitely needed.
After mulling over all the options and looking at what people are installing in their classic Chevys these days, we decided to go with an overdrive automatic. Since the Chevelle is already set up for an auto, converting to a better slush box would be easier than a full manual trans conversion (at this time at least) and allow us to get the car back on the road quicker so we can start enjoying it.
TCI, or Torque Converters Inc., was originally started by funny car racer Bill Taylor in 1968, to supply hardcore racers with heavy duty torque converters and transmission components. Today, the company is part of the Comp Cams Performance Group, and has a much expanded line of transmission parts, and complete transmissions. When it comes to automatics for GM cars and trucks, TCI offers a wide variety of electronic and non-electronic options for enthusiasts and racers alike, including the Powerglide, TH350, TH400, 200-4R, 700-R4, 4L60/4L65, 4L80/4L80E, and its own in-house designed 6X six-speed automatic transmission.
For our car, we decided to go with a tough 4L80E trans with stand alone controller, that will gives us more control over setting shift points and overdrive engagement versus using a stock TV cable setup.
Part 1 will cover the assembly of the transmission, while in a later issue of Super Chevy, Part 2 will show the actual installation of the 4L80E in our '67 Chevelle, including the stand-alone controller that will let the fully electronic transmission interface with our non-electronic big-block.
To save some mess and make all the parts more visible, this assembly takes place dry. Normally all clutches would be soaked thoroughly in automatic trans fluid before being installed.
A Brief on the 4L80/4L80E
In the early '90s, GM needed a heavy duty overdrive automatic that could fill the same role the venerable and rock solid TH400 did, but with the gas savings of an overdrive. So, the engineers designed a new case that would accept a majority of the TH400's strong internals, but also provide room for an overdrive gear, along with some other heavy duty refinements. Like the TH400, the 4L80/4L80E use a 2.48:1 first gear, 1.48:1 second, and 1.00:1 third, with a 0.75 overdrive and 2.07 reverse. Later in the '90s the unit received a fully electronic upgrade, adding the E designation to the model number.