I have the factory fitted rear locker in mine, works well and has been faultless, does take a little LH and RH steering input while driving forward 5-10m to engage. Not sure how hard they are to retrofit. In the front I have a ARB (6-7 years...
Woodspoint area, not far from me, those two tracks I hadnt done in a number of years. Its a old Gold mining and logging area.
https://maps.app.goo.gl/EnSqxeUa9EbkhigT9
I would say there are numourous small internal differences, everyone here justs buys a whole H152, swaps the required parts for their engine and off they go
I do laugh at all manufacturers claims of improved efficiency, it just does not translate to the real world. What does partially translate is improved emissions but mostly now days that is done through after treatment, not actual engine...