OK, it is probably best to use common sense here… go look at the bike, stick your finger under the mudgaurd and see it there is enough clearance. If you can get your whole finger in the answer is yes!
It is usually best to replace what is on your bike with like for like, but I don’t think a 65 is normal. It will make the bike stear a bit quicker but most modern sports bikes have a 70.
My old Hornet had a 16" 130/60, same as the old fireblade but new bikes use 17" 120/70.