In an era where overhead-cam engines were reserved only for a few expensive sports cars, Jeep's 230ci OHC Tornado six was unusual. In two-barrel form, this engine was rated for 140 hp, despite the fact that the actual dyno certification test showed 155 hp. A lower-power 132hp 1-barrel engine was optional. The 230 OHC was the only available engine until 1965. Early that year, a 327ci V-8 was added to the options list and later the Rambler 232ci OHV replaced the Tornado as the standard powerplant.