Yes, My F is faster than the K. They have different carbs on each bike but I think it has more to do with gearing. I haven't counted the sprockets but I should!
The factory gearing is the same on both models.
I can't believe any difference in factory carbs has any difference in power output. They
were all rated the same from the factory.
However, within any production run, there are individual examples that are just built a bit better and have all the tolerances skewed toward a benefit.
Then again, don't overlook the importance of weight. Four exhaust pipes simply weigh more than just one.
Then there is the extra weight for oversize tires, and other "additions".