That's in 3rd gear, going around 60 kmh. Yep,2nd gear at around 70 kmh at around 3000 rpm is what you want. Speed or gear isnt important, it's the revs that matter. This is from long observation of my temp gage. Hill climbing at 2100 rpm you are in SERIOUS risk of burning up your torque converter. It may feel nicer for the engine but the tranny will not be happy at all and your T/C will be up to 150 C or higher. Even 2500 is not enough, I find I need to be up near 2800+ to keep the temps down; i also notice EGTs are lower as well. Don't forget, this is assuming you can't stay in lockup. If you can climb that hill at 2100 rpm in TC lockup you will be just fine. It's the TC that generates all the heat. As Rodney says, the TC in the A440 is not the best. This is also why I am dubious that the extreme valve body will be a full solution. It has lockup in 3rd, but what is really needed is lockup in 2nd. There is not a huge difference revs wise between 3rd and 4th. Even with an extreme valve body and an external cooler, you may find you need to run up steep hills in 2nd. And don't forget, you need the temp gauge in the outlet union between tranny and cooler. A temp gauge in the oil pan won't tell you how hot your T/C is getting. A 74 is a lot lighter than my 80-series and the HZ doesn't kick out nearly as much power, so you probably won't generate as much heat as I do.
Now, if only I could have a electro-hydraulic later-model A440. With that tranny you can install a manual TC lockup switch that will lock the TC in whatever gear you choose.
