I don't know...I think the R series 4 cylinders have proven themselves over and over and over again to almost always exceed 200K miles and sometimes twice that or more on a regular basis.

I think that almost all 4 cylinder head gasket problems can be traced to the motor being overheated at some point. And I don't think headgasket failure in the 4 cylinder is really that common.

The reason you hear of all these problems with 4 cylinders instead of the V-6 is because there far more 4 cylinder Toyota trucks out there. From 1979 through 1987, there were only 4 cylinders. And from then on, the V-6s only comprised of half or perhaps far less of all the truck produced.

I won't argue against the Toyota V-6 being an excellent engine. After all, it is Toyota designed and has an overbuilt quality to it. Toyota was able to use the same block as the 3.0 V-6 and pump 1/3 more power out of it and even more than that with the supercharger when it designed the 3.4 V-6 and it's still factory Toyota reliable.

They just screwed up the head design or gasket design on the 3.0 V-6 somehow, that's all.

But for simplicity sakes, there's a lot to be said for the old reliable 22R motors. They are cheap and easy to work on and since so many were made from 1982 through 1995 (Here in the U.S.) parts are more than abundent.