I'm not sure about this but I heard that the problem was that the rear cylinders on both side were the problem & it was cause the way the exhaust was routed over the top & that would help heat up the rear cylinders Is that true BLACKDOG 
I *believe* that compounded the problem, but wasn't the cause. The cause itself was the composite material of the head gasket. Time and excessive heat would cause the headgaskets to deteriorate, and eventually blow. the rear most cylinders are subjected to more heat than the front 4, but with the newer headgaskets, that in itself shouldn't be a problem
Now that you mention it, I wonder if that is why many people claim that they run better with more miles? Could it simply be that the constant heat over time essentially "cooks" everything together, kinda sealing it all up even more?
I know its a stretch, but I guess its possible?
Aside from all this
yota85truck, if you run a compression test, have the vin # run by toyota, and it all checks out clear, I'd say the runner is a pretty good deal. I'm on my 3rd 3.0, but its still a fairly reliable motor I have yet to lose one due to headgaskets in all honesty. I lost my first one due to cold temps, and only having water in the system (previous owner did that, I didn't check it before I went to reno in the winter
stupid newbie mistake ) thought it was the hg, but after doing them twice, discovered it was the block. 2nd motor I bought used from a private party, and the rings went after about 6 months. This 3rd motor was prior to the hg recall ('88) and has been running like a champ. Keep it cool, keep it full of oil, stay on top of leaks, and it will serve you well. Keep in mind that this is the worst motor toyota made, and they are still out there, with 200, 400, I've even seen one with 500K miles on it.
If you have any other questions, feel free to PM me or ask here. I will try to answer them to the best of my ability.
