I've been debating between duracell agm and x2 power agm (both stocked by batteries plus) to replace my current battery when it dies. This may push me towards duracell to save me some coin.
Installing an external cooler is really not that much work since you're just tapping into the existing system. It's really a no brainier if you plan on keeping your truck long term.
My pan temps were hitting ~220 on long mountain passes before adding the Hayden. After adding a cooler, they stay under 200. Even if you’re not towing, reducing heat helps longevity. These transmissions don’t love sustained high temps.
I have a 678 in mine since the transmission already has a thermostat. Some people get the 698 and pin the thermostat in the transmission. I think the 698 thermostat opens at a lower temperature.
Absolutely necessary. I would also add an inline filter and a way for you to monitor torque converter temps and pan temps. Monitoring torque converter lockup also helps with transmission temps.