Keith,
Regarding the cams you mention, I was talking to member MastaN about 10 years ago and he had done a straight swap on his 865 Speedy with cams from a 790cc.
He reckoned it was the best single performance upgrade he had ever done (his words).
I don't know if it makes a differece in any way but just mind they were both carbed models.
Hope this helps.
