https://www.repairclinic.com/PartDetail ... 0S/1604430
https://www.repairclinic.com/PartDetail ... 84/1611261
For some reason I thought that the 7.. was a improved replacement for the 2.. but actually forgot and ordered a 2... Checking suppliers though the 2... never shows being replaced by the 7... .The engine that I am working on called for the 2.. so it should work (for the usual length of time)
Although now looking at the images the 7.. one , it has a 31 stamped on it so maybe it's for the 31 series . Should work on the 28 I expect. Pretty sure I put one on a 28 once.
Update:oops the 31 series has a slightly larger bore than the 28 so I better make sure I use the right gasket.