Engine Options
There were three Toyota pickup four-cylinder engines used from 1979 to 1985: 20R, 22R, and 22R-E. There was a 21R, but it was used only in Japan. The '79-'80s had the 20R carbureted 2.2L engine; the '81-'83s were fitted with the 22R carbureted 2.4L engine; and '84-'85s came with either the 22R carbureted or the 22R-E electronic fuel injection.
It's easy to tell the engines apart--just read the writing on the wall. On the driver side of the engine behind the alternator is a flat, machined area with the engine designation. Also look on the nose of the valve cover--if you're lucky there will be a decal with the original engine size. Or for more of a challenge, look for the 20R's round intake ports; the 22R has square intake ports. The intake manifolds are not interchangeable.
All of those four-bangers can be easily upgraded for performance. One drawback of the solid-axle Toys is that they were never available with a V-6.
Differentials
All '79-'85s came equipped with 8.0-inch (same as the 7.8-inch) solid axles. The experts we spoke to agree that the solid-axle setup can't be beat when it comes to hard-core rockcrawling, and Jim Sickles from Downey points out that these trucks can be lifted less expensively than an IFS truck.
But here's the cool part--the front and rear axles each feature a dropout pumpkin, and it's interchangeable from front to rear. The only distinction between the pumpkins is '84-and-newer models have a different rear pinion bearing.