Looking at replacing my worn out chain rings and would like to change them around a bit if possible and looking for advise / experience in doing so before ordering stuff.

Running XT 38 - 26 rings and often find myself in the highest gear wishing there were one more to use. So I'm wondering if it is possible to fit a 40 big ring and keep the 26.

Looking at CRC there seems to be preset options: 40 - 28, 38 - 26 and 38 - 24 so I'm thinking that maybe the size 40 won't fit the cranks or can't be combined with a 26 inner for some reason.