The old pushrods were mushroomed slightly on a couple ends so I figured I'd just replace them while I was in there.
When the van first overheated on me it was when I was driving it home going over a long, steep mountain pass. I thought I pulled over in time, but maybe not. Or maybe it already had a small leak when I bought it, as there was some head gasket repair stuff in the glove box but it hadn't been used and I didn't see any signs of a bad hg. It also didn't have the fan shroud on when it first overheated so I thought that was the problem, but after fixing that and eventually going with a better electric fan (among other fixes) it was still overheating and shouldn't have been. We nnoticed some slight bubbling one day at initial start up with the rad cap off, so I figured it had to be the hg. If your ac doesn't work I'd recommend taking off the condenser, it really blocks air flow, much more than my 2wd did, although the condenser on it was vertical up against the radiator. Losing the ac also saves some weight, which in my case is definitely something I have to consider. I have 2 medium to large size dog's, and 2 adults, a roof top tent, roof rack with recovery gear and some other supplies, extra parts, hot water containers and everything else inside we need such as cook stove, food, chairs, drinking water, solar equipment, etc. The van is rated to hold 7 passengers and luggage, so it definitely can handle it and larger coils are also an option, but anything I can do to help it out I want to do. Especially if it involves getting rid of something that is dead weight for me anyway. Just the condenser and compressor took at least 100 lb away and you can use the 12 volt fans from the condenser for a ppusher fan or something. Also check your hose of death, mine was easy while doing the head gasket but you can cut an access behind the front seats. Mine already had one cut as well. From my research on it though the main things are to run a toyota oem thermostat from the dealer ONLY, keep coolant clean, system in good repair and pull over as soon as you notice any signs of overheating and these things are good to go. Bit removing that ac will definitely allow better airflow. Mounting auxiliary heater cores can also aid if you want ac