The Tremec gearbox features shorter first and second gears than expected, the shift lever topped by a six-speed knob that Vigilante designed by 3D-scanning the original Jeep four-speed pattern.

Instead, the base model Jeep Wrangler will keep its 285-hp 3.6-liter V-6, but only with a six-speed manual. Previously, the slushbox was a $4500 upgrade. The automatic transmission will remain ...