Izak, I am sure she does not know, but from looking underneath both, the Y60 and the Y61 looks the same underneath and I am sure that when they designed the box, the Y60 was what they designed it for and they never realised it would fit into the Y61.
A person from the 4x4 Community Forum, at the time I fitted mine, asked about it and I gave him my impressions and on the strength of that, had one fitted. He came back on the post and said he had it fitted and was happy. I never followed up with him and cannot remember him ever coming back onto the forum with problems with the tank.
Just a word of warning, do not just have your stainless tank made by "elke Jan rap en sy maat" operation. It must be someone like the well know offroad equipment manufacturers. Their reputation is at stake here. They will have done their homework and they will use the correct grade of stainless steel, there are several grades of stainless, some are magnetic, some are not, some are hard brittle, others formulated to be more bendable and pliable.
Some grades it is required to be preheated to a specific heat range before any welding is done. The trick is to know which grade to use. Go and see here (
https://continentalsteel.com/stainless-steel/grades/ and
http://www.worldstainless.org/Files/iss ... g_2013.pdf) and see the characteristics of the different grades.
The big problem is that the commercial outlet you go and enquire from, is not where the designer and the manufacturer sits, and they have be told that they will not make "one offs" full stop. So if a tank is not commercially available, what happens?
They guy wanting the tanks goes to a buddy who has a buddy whose ex-girlfriend's cousin works for some engineering company, who has spare capacity due to lower demand, and they will make one for you. They have a couple of sheets of 1.6mm stainless steel or even worse, will go and buy the cheapest offcuts to make a tank for you at a really good price. The big problem is that these guys have not researched the best quality and grade of stainless to make the tank from. Their welder just welded up a tank with welded on fastening brackets (maybe without gussets!). It was tested by blowing in air at say 5 or 10 PSI and did not leak when put into the welder's swimming pool at home. It fits, they even help the guy install it (without supporting weight carrying straps) and the guy goes off, happy that he now has a long range tank.
The big issue is how long is it going to last and if it breaks, how do you fix it in the Kruger Park in December when it starts leaking?
Another thing the guys in the know do, they make it with bends (not welds) on the long sections, just welding on the smaller sides and the top, so that the main weight bearing sides have bends and no welds (that is why OEM tanks are stamped out of a single (mild) steel plate (nickel or tin plated afterwards) for the bottom half of the tank, another stamped out one piece for the top, and its is machine seam-welded together at the seam where top and bottom halves join). Then they also weld in baffle plates that not only stops the slosh, but actually strengthens the tank. These plates have quite a few (6 or 8) biggish (30mm) holes for fuel movement. If the baffle plate does not have those holes in, it has a lot of pressure from moving (sloshing) fuel inside the tank, and the baffle may eventually tear away from the tank side and tear the side of the tank in the process. These baffles also have 15 or 20mm wide, 90 degree folds at the ends, to create a flat surface to weld (onto two sides of the 20mm wide flat bent piece) on the inside of the tank. The welds are also not long welds, that cause a lot of heat, but several smaller 20mm runs.
