hi Neil, actually the 3338/3342 rear spring ref is more confusing than it looks like. In the latest OME catalog, you're right it is mentioned 3338. But in previous catalog it is 3342 (for medium also) see attached. Also, some other informations makes the 3342 more believable : 1/in "equip'raid" website, well known in france, they sell 3342 for diesel version 2/in all websites and IA reasearch they mention 3338 specifically fo petrol 3/you could think this is wiered that latest OME catalog do not mention "petrol" version but only diesel. It looks like they made a mistake in the latest catalog mixing petol and diesiel information. I was completly confused and asked Equip'raid to confirm with ARB Europe. They came up with conclusion that 3342 is the right ref for diesel (see attached). This spring is shorter than 3338 and bit more "strong" but this sound logical as the 3338 is a bit higher and softer to absorb static battery weight. As far as i have understood the 3342 is shorter (no battery) and a bit stronger only to compensate dynamic (when you break, as the front is much heavier, it will help rear keeps stable). Well, if you have any other information in this very confusing ref from ARB please let me know ! Did you already monted your 3338 ? does it look and feel ok ? any pic ? thks