Andrew, easier to find hens teeth around these parts.
But seriously, after looking fruitlessly for ages for a petrol air cleaner, I had wider pipes installed in my air cleaner for the petrol engine by TNT Performance Exhaust.
Made a huge difference to the power and a small difference to fuel consumption. A decent exhaust place would be able to do it for you and the actual dimensions of the filters themselves are not that different. The diesel cleaner has a 50mm pipe while the petrol one has 76mm.
Stu, I was looking at that option for my 606 conversion but they were all pretty bulky. Ended up shoehorning a 230/280 petrol filter under the bonnet.
According to calculations I did at the time it would have been too small as well but so far the blocked indicator has only been triggered once and it could have been my doing as well.
OK cool, I had a 280 filter housing from the start - Trevor advised to use the larger one for turbo application. Its a bit of a tight fit with the upgraded booster, but all fits.
I had to rotate it in its holder, and change the pipe to the turbo, makes the plumbing easier.
If i do cut and weld, (as per Anthony) has anyone rotated the entire filter ie so that the inlet faces backwards for easier snorkel plumbing? I saw Anthony's Bravo snorkel and it looks the nibs, but has the long pipe under the fender going forward which might be nice to avoid.