By way of introduction, I am in the U.S. and work with the Buick 3800 in a Reatta. The specific reason I am asking here, is the almost total lack of information on the Holden 3800 on my usual technical forums. I reckon the proper place to ask is where there is the greatest knowledge base. This started when I was looking through a Silvolite piston catalog for possible shelf stock pistons to use for my next build. I found 1751H which is listed as for a '97-'04 Commodore but no other model detail. The bowl shape with the raised island in the center made me wonder what the purpose is? The .905" offset pin and 1.449" compression height would be about zero deck on my 9.5" deck block with a stock 6.4" rod. Speculation from some is the shape helps soften the expansion enhances detonation resistance. Perhaps naively, the most obvious feature of the engine exterior, the intake manifold, looks just like what we would call the pre-Series I 3800, the LN3. What we call the Series I and II are all Tuned Port style with the long curved, bag of snakes, runners, with the Series II being a lower deck where almost nothing interchanges with earlier models. I am sure what is under that intake manifold is likely different than what I would expect. If there is gallery with photos of the engine interior parts that would be helpful.