That's Larry Minor's 409-powered...
That's Larry Minor's 409-powered and stretched CJ-5 staging for the hillclimb at Glamis in 1964. Note the triple (yes, triple) tires on the rear.
World War II Jeeps had 6.00x16s with what was referred to as a non-directional tread (NDT) design. Later, Jeepers referred to these tires as grave diggers for obvious reasons. Not only that, they were flat out dangerous on rain or icy, slick roads. It's absolutely amazing the military stuck with this tread design for some 50 years.
On my first Jeep, an MB, I used some 7.00x16 eight-ply bias truck tires. The added height raised the gearing to improve highway speed, but the ride quality suffered with the stiff sidewall. Then again, I don't think that was a factor because we simply expected Jeeps to ride poorly at the time. With the civilian CJ series of vehicles, Jeep kept the 6.00x16 size as standard with an optional 7.00x15 until the 1957-'60 period when it started offering quite a few different 15-inch options, the most popular being the 7.60x15 Suburbanite. Most unusual for the time were some 900x13 Rib Sand-Service that added $283.70 to the Jeep's price. I only remember seeing a couple of Jeeps equipped with these tires, and one of them belonged to the Los Angeles County lifeguards; it was used for beach patrol. The other set was on Clarence Shook's Rancho Supply Jeep.
After that, Jeep didn't seem to be too concerned with a large tire option until about '71 when it offered an 8.55x15 Suburbanite on a 6-inch wide rim. There was also General Tire Company's Dual 90. It was an 8.50, but would fit on an 8- to 10-inch wide rim. With lowered tire pressure, this offered good flotation in sand. One problem was that the tire would cup in the center and again at the point where the sidewall met the tread shoulder, which resulted in an unequal pressure footprint. The real problem was that we were exposing the tire's sidewall to possible damage. However, the tires were bias-ply and made with nylon cord, which is stronger than polyester cord, so we seemed to get away with it.
The first really wide flotation tire that was readily available was the Armstrong Farm Implement. With straight, parallel-to-the-circumference grooves and with the shoulder blending into the sidewall, it flexed quite well at lowered air pressures, and it offered an equal footprint with no high and low points. Dick Cepek got his start in the tire business selling this tire. I bought my first set right out of his home garage. The rounded design and low tire pressure let the tire envelop an object, but they really sucked in mud or snow. Some of us got out the grooving iron and made a tread pattern of our own design.
I even tried using some Goodyear Indy-type tires that offered over a foot of tread on the ground with a soft rubber compound that stuck to the rocks like a lizard's foot, but the thin sidewalls were subject to rock damage. I still thought that they looked cool on the street.
By the '70s the tires of choice were the Gates Commandos that first came out around '68. Western Auto also sold a similar tire called a Sand Blaster. In fact, it became a real popular tire with the off-road racers, be it a buggy or a fullsize truck. Most likely the most popular tire of the late '70s and early '80s was the Armstrong Tru-Trac because its wide, 11-inch tread and 33-inch height that became the standard to judge other tires by. Another interesting tire of the time period was the Pos A Traction by Inglewood Tire Company. It was 2911/42 inches tall and had a 9-inch tread width that was made up of 1-inch individual blocks. Yes, it was really noisy going down the highway.
Playing in the sand dunes at Pismo Beach or Glamis was big-time fun, but the need for more traction developed as horsepower increased. The grooved Armstrongs just weren't doing it. Before all the trick paddle tires were available, we would cross groove dragster slicks. It was a very time-consuming project, for sure, but they sure worked good for the time. Most of them were in a 16-inch rim size, and the M38A1 military had 16-inch rims with safety beads, unlike the stock Jeep rim of the time. We would scrounge these and widen them anywhere from 10 to 14 inches. We ran these tubeless and poured in what seemed like a gallon of tire sealant. Out at the Dumont Dunes one time, I unfortunately found the perfect rock to punch a thumb-size hole in the tire. Not to have a perfect weekend of sand running ruined, we broke down the tire, cleaned out the tire sealant, and patched the hole with multiple layers of duct tape. Then not having a large enough tube for the (then) super-wide rim and tire, we drilled another valve stem hole on the backside and inserted two tubes, reinflated the tire, and ran it for two more days like that.
One of the most unusual tire combinations I can remember seeing was on the CJ- 6 of Larry Minor, a potato farmer, Baja winner, and AA/FD champion. In his quest for sand traction, he was running not just duals but triple wheels in the back and doubles up front on his 409 Chevy-powered Jeep at the Glamis illclimbsin November of '64.
But what about wide rims? Chrysler Imperials shared the same bolt pattern as Jeep and were 6 inches wide, a full 1.5 inches wider than the stock Jeep rim. Plus, they had a safety bead, unlike most rims of the time. This helped hold the tire seated at lowered air pressures.
It wasn't until the mid to late '60s that fully stamped, one-piece wide rims were available. For sand performance on a low budget, we would make up a set of duals by actually welding two wheels together at the rim flanges with the center removed of the outer rim - a poor man's dualie. Want to have a full afternoon of fun? Try mounting the tires! Those that were really skilled would make up some flanges so the two rims could be bolted together. Vic Hickey had made up a few spacers with a special hub to mount dual tires around '64, but they were pretty scarce. Besides, they cost $35 a pair, money that I didn't have.
We used to make a lot of our own wide rims. Luckily, I had access to an antique belt-driven lathe that would swing a 16-inch rim. First step was to cut the outer portion of the stock Jeep rim off and do the same with the inner section of a Lincoln rim and then weld the two sections together. If I remember right, we could get about 8 inches of width. Anything wider and we would cut a rim (Chrysler Imperials being popular due to the safety bead and same bolt pattern as a Jeep) in half, have a local blacksmith shop roll us a steel band, and weld this in place. A wheel jig made up of two large steel plates mounted on a spindle clamped the sections together and kept it (well, almost anyway) true. They were all stick-welded together, and we were trying to run tubeless tires by now. In an effort to solve the porosity problem of our not-so-tight welds, we used lots of paint hoping it would seal the air leaks. I made lots of wheels this way. Yes, there were companies that made wide rims in a similar manner, but, again, they cost more money than I had at the time.
Now one can pick up a catalog and find a bewildering selection of wheels in both aluminum and steel that are just a phone call and credit card away. It's the same with tires. In fact, the array of what is available is so staggering that trying to pick the perfect tire is seemingly impossible.
 The Goodyear Terra Tire appeared...  The Goodyear Terra Tire appeared around 1968 in a 15.5x15-inch size. These were low-pressure agricultural tires that worked great in muddy conditions and not so great on the street. |  In 1962 I built my second...  In 1962 I built my second set of wide wheels using a 6-inch-wide Chrysler Imperial rim with a 4-inch rolled steel band welded in. That's a stock Jeep rim on the right. |  In the mid '60s and '70s and...  In the mid '60s and '70s and even in the '80s, the Armstrong flotations were the in tire. Its straight grooves didn't offer a lot of traction in the mud, but were flexible enough to work quite well in rocky terrain and on desert trails. |
 The Goodyear Terra Tire appeared...  The Goodyear Terra Tire appeared around 1968 in a 15.5x15-inch size. These were low-pressure agricultural tires that worked great in muddy conditions and not so great on the street. |  By the late '70s and early...  By the late '70s and early '80s, the Armstrong Tru-Trac became the tire that all others were judged by. Even today a similar tread design is in use by almost every tire manufacturer. |  The Gates Commando XT Special...  The Gates Commando XT Special in a 10-15 size was a popular tire in the late 1970s and 1980s. Note that the rim has been widened by being cut in half, a rolled band inserted, and a second inner half of a rim added to the outside to make a full 10 inches of width. When you really look at the tread, it didn't offer much in the way of forward biting surfaces or edges, but it sure worked well for high-speed dirt cornering, which the desert racers liked. |