The only issue which is not really an issue is that the newer cases that come with the 2010 carb have a small indentation machined in the surface that sits flush with the base of the carb. This allows a second small o-ring to used around the carb neck. So on the older case which does not have this indentation machined into it the carb will sit up about .5mm (so if you can imagine there will be a small gap between the carb base and the case because of a little o-ring being sandwiched between the two). Just remove the small o-ring (which works as a secondary seal) as there is the big o-ring in the case that fits around the carb neck and seals it just fine. That is all that you are going to see and again there is absolutely no issue running the carb with the small secondary o-ring removed. Hope this helps!