Sheet Metal Tunnel Extension | 1964-1972 GM A-Body & 1965-1973 Mustang/Cougar
Key Features
- MDL Exclusive - custom-designed specifically for T56 and TKO 5- and 6-speed conversions
- 18-gauge steel construction with press-brake forming for consistent fit and structural integrity
- 38.3 inches long - provides full clearance for modern overdrive transmissions
- Tapered profile: front measures 10.6 in. wide x 6.8 in. high, rear narrows to 4.8 in. wide x 3.2 in. high
- Fits 1964-1972 GM A-Body (Chevelle, GTO, Tempest, El Camino) and 1965-1973 Ford Mustang/Mercury Cougar
Description
A TREMEC T56 6-speed transmission is simply too large to fit into an OE tunnel - these transmissions run over 34 inches in overall length with case dimensions that dwarf anything the factory ever installed. When you add header clearance into the equation, attempting to use a stock tunnel becomes an exercise in frustration. This MDL-exclusive sheet metal tunnel extension provides a purpose-built solution that eliminates complex custom fabrication while ensuring proper clearance for your T56 or TKO conversion.
Manufactured from 18-gauge steel using precision press-brake forming, this tunnel extension delivers consistent dimensions and clean bend lines that make fitment straightforward. The tapered design follows the natural contour of the transmission case - widest at the front where the main case requires maximum clearance, then narrowing toward the tailshaft housing. At 38.3 inches long with front dimensions of 10.6 inches wide by 6.8 inches high, there's ample room for the larger TREMEC case profiles.
This extension fits the most popular classic muscle car platforms: 1964-1972 GM A-Body applications including Chevelle, GTO, Tempest, Le Mans, and El Camino, plus 1965-1973 Ford Mustang and Mercury Cougar. Installation requires cutting the existing factory tunnel and welding the extension in place - standard sheetmetal work for any competent fabrication shop. Note that the tunnel support brace is not included and may be required depending on your specific chassis.
Rather than spending hours fitting, trimming, and hammer-forming a custom solution, this MDL-exclusive panel gets your tunnel modification done right the first time. Made specifically for the transmission conversion market, it represents the kind of purpose-built solution that only comes from a company focused exclusively on manual drivetrain upgrades.
Kit Includes
- One 18-gauge steel tunnel extension panel, press-bent