Where the carburetted six used to sit there’s now a 5.7-litre LS1 V8 backed by a TH400 automatic transmission
80-series and the 45 body placed on top ready to mock up the body mounts and bar work. The body has been set back on the frame to push the front axle forward for a better approach angle. Surprisingly this meant the wheelbase between the 45 and 80 were almost bang-on identical, with only a slight re-work of the rear wheel arches all that was needed to dial it in. With the wider 80-series axles pushing the wheels and tyres out a further 100mm each side, Billy constructed a series of reinforced tube wheelarch flares that also tie the front and rear bars into the sliders. The whole lot not only gives Billy the confidence to slip and slide the 45 through rocky terrain, but it substantially reinforces the chassis against twisting.
While the body was off for final welding of the bar work and body mounts, a new crossmember and engine mounts were burned into place for the updated drivetrain. Where the carburetted six used to sit there’s now a 5.7-litre LS1 V8 backed by a TH400 auto transmission sending power to both axles through a Chevy-sourced NP205 transfer case. Just for good measure Billy shoe-horned a GTX42 turbocharger into the already cramped engine compartment, with a front mounted intercooler slotted in between the radiator and support panel. Despite being a low boost set-up with only 8psi pushed through the intakes, upgraded injectors were required for the increased fuel demands. Hanging off the back of the turbo is a full 3.5in custom exhaust with a Hooker muffler. On its first run on the dyno with a mild tune she pushed out 340hp at the wheels, which works out to be in the mid-400s at the flywheel – although with a more aggressive tune in the works this number should jump to 400 and 500 respectively. Serious ponies for an old Troopy.
However, it wasn’t all sunshine and rainbows getting the new drivetrain working. With the transfer case’s rear output centred in the chassis and the 80-series diff centre being offset to the drivers’ side, a GQ Patrol rear axle was needed to get things back
When is a 45 Troopy not a 45? When it’s an incognito 80. 80 Series underpinnings bring coil sprung comfort and control to the old bus. 37-inch tyres look almost cartoonish – until the V8 starts to bark.