The overhead cam Tornado six in Brian Chuchua's drag racing CJ-6. Yep, those are three Webbers on the intake.
Harry Buschert, who had a farm machine shop in Hemet, California, may have been the innovator of using the longer six-cylinder Jeep pickup input shaft in the CJ's transmission. His adapter, made up of two thick steel plates sandwiching a welded-in spacer, was my choice in '64. That same year at the Pismo Dunes, I remember seeing a 426 Chrysler engine along with its long ram intake for the twin four-barrel carbs in a CJ-5. I have no idea what he was using for a transmission; guess I was too wowed by the engine.
Soon to follow making adapters was Hoosier Machine in the Pacific Northwest. Other guys like Johnny Dias built some for friends and "Mr. Jeep," Brian Chuchua, by '63 was offering adapters for just about any engine, as well as performing engine swaps in his Fullerton, California, location. Jim Hicks of Hicks Muffler shop (later to be Hicks Jeep Shop) and Harvey's Jeep Shop were also pioneers on engine swaps. Soon, two major businesses were built for supplying adapters. Lloyd Novak's Novak Adapters started up in the early '70s and chose to stay with only adapting Jeep components and so still does the business acquired from him. John Partridge at Advance Adapters (originally named Advance Tooling and Engineering in '69) followed suit with their own versions, as well as adapters and such for other vehicles.
With a small-block Chevy, especially in a flatfender, distributor clearance is always an issue. This is a really crude example of how one person achieved this.
Motor mounts were pretty much a homemade choice. However, Chuchua was supplying motor mounts along with Con-Ferr and companies such as Western Truck Sales in Phoenix, Arizona. Chevrolet cars and trucks weren't using the side-block mounts of today, but the mounts came off the front of the engine. Patterns floated around throughout the various Jeep clubs of a yoke to be torch cut from a steel plate that bolted behind the crank pulley and extended to each side of the frame. The ends of the yoke were then mounted to the four-cylinder Jeep motor mounts now bolted to the top of the frame.
Chevys became the engine of choice, most likely, due to their availability as well as adaptability. The rear-mounted distributor was, however, no end of trouble and the firewall had to be modified. On a CJ-5 this could be accomplished with a big hammer, but on the flatfenders it usually meant a cut into the firewall. Now the distributor set back in under the cowl, and it was difficult to remove the cap and impossible to remove the distributor itself with the engine in place.
The 1949-53 Ford flathead V-8s were once popular engines due to their availability and compact size. Note that this one sports an alternator conversion. The smallish air filter leaves a lot to be desired in filtration ability. In case you're wondering, the large can on the right rear of the engine is an oil filter.
The 215 aluminum-block Buick and Oldsmobile engines were popular, as well as the Buick V-6, especially in the flatfender Jeeps because their compact size, front-mounted distributor, and light weight made for easy fitment. Other than replacing the L-head four with an F-head four in my military MB, the V-6 Buick swap was the first engine swap I did in a Jeep back in '64. There were also a few of the old Y-block Fords used and even some of the big-block FE series of engines. When Ford came out with its lightweight 221/260-cubic inch V-8s in '62, these also became a big hit once they were available in salvage yards. These engines weigh in at 475 pounds, not all that much heavier than the four-cylinder that they replaced and some 55 to 60 pounds lighter than the Chevy V-8. Oil filter clearance was a problem on the Fords and, at first, some sort of a remote filter was used. Later, it was found that the four-cylinder Ford tractor filter was a lot smaller and a direct fit.
The 153-cubic inch Chevy II four-cylinder became popular because it was considerably lighter than the F-head Jeep engine, and being four inches shorter it fit nicely in a flatfender. Also, lots of the Chevy V-8 parts were interchangeable with it.
A Ford Falcon six at 170 cubic inches made a pretty easy swap but, naturally, you had about a 3-inch firewall recess to make. The factory Ford clutch disk has the proper spline, but you had to make up a bushing for the throwout bearing. The upper bolts of the bellhousing matched up, and there was enough room to drill new lower holes.