Thanks again Gerg and Dougal for all your info so far.
As mentioned in the first post, I'm not after big power, just a nice, safe, reliable increase as the HJ is my daily driver. I was originally thinking around 7-10 psi if possible.
From this thread it seems redline for a 2H is around 4100 (post 33). Also seems most have the 2h revving 2500-2800rpm when cruising on the highway. So is the 2700rpm mentioned earlier in the thread going to cause issues?
https://forum.ih8mud.com/diesel-tech-24-volts-systems/290841-max-rpms-2h-2.html
I do a fair mix of driving in it, but it would see a 2-4hr trip at 100-110km/hr a couple times a month. Also a large hill where I am maxed out in 3rd gear for a good minute or so (and doing 30km/hr under the speed limit).
Could one of you give me a quick conclusion on what I can expect if I run HX25 on the 2H?
Thanks.