DB,
Do you have an 848 kickstand available right now? The easiest thing to do would be to see if the mounting holes from the 748 and 848 engine case match up. If I think about it I can measure my bikes this weekend.
Do you plan on using the kickstand switch? They might be different between the two models. You can always put a jumper in the switch if that's the case.
You may also want to measure the length of the two kickstands, if the 848 kickstand is shorter than the 748 kickstand then your bike may rest at a not so confortable (to you) lean angle when on the kickstand
