My understanding on this is that the castings came out slightly different, so they were sized according to this.
Precision in this game is what seperate the men from the boys. When you want something that moves 32,000 times a minute to last, you better be dead balls on accurate. That's at least how I see it.
Apparently, cylinder come marked as A, B, or C. I've had both A and B Husky 262 cylinders here. The B's are much more common. No "AB" cylinder exists, but AB Pistons do and can be used in an A or B cylinder.
The meteor box on top measures 47.95mm. So you should get .05 mm of side clearance or roughly .002"-what we all look for. I can't find a pic of the A piston box I had, but I will try. It's a slightly smaller dimension to fit into a slightly smaller cylinder.
At these tolerances, compression would be the same with the wrong piston. But a smaller A piston in a C jug would be loose and slap the skirts, and a B piston in an A jug may seize if it expands too fast.
You guys know I do a lot of 26's. The A is much more common than the B cylinder on them. I had a sweet KS "B" jug that took a B piston. That same piston had its dome cut and was to go into an A jug. It bound itself at the top of the A jug. An A piston worked fine.
I think this is a case where you get some lattitude, but I personally match the piston to the correct jug. I'm too neurotic not to.
FWIW,
@Welder56 taught me this when he got a 262 from me that I had bought off of
@Landmark.
