The 3-speed option is the full indicator plate, where as the 4-speed overdrive option is an overlay.
Our products allow our customers a viable solution to retain the factory appearance of their car without sacrificing performance. "In the olden days" many GM vehicles came with either a Powerglide or a 3-speed automatic such as a TH350 or TH400. As time went on, GM released a variety of transmissions that had overdrive capability. Overdrive simply means that the output shaft of the transmission rotates faster then the speed of the input shaft from the engine. The result was better fuel economy, as well as more gentle highway RPMs. Some of the popular transmissions in this category include the TH700-R4, TH200-4R, 4L60, and 4L80E.
The main issue arose, however, when hot-rodders and car enthusiasts began attempting to swap these transmissions into their classics the factory shifter no longer functioned properly. This is where Shiftworks comes in. From conversion kits for factory floor-shifters, to complete new shifter packages, we enable hot-rodders to upgrade their cars transmission, without moving away from a completely factory interior look. With new shifter detents, transmission components, and console indicators designed for 3-speeds, 4-speed overdrives, and even for some applications, 6 & 8-speed automatics, Shiftworks products allow you to make your transmission swap as if your car came that way.
| Make | Model | Years |
| Chevrolet | Impala | 1966 - 1967 |
