This is basically very old news given that 1500's are out of production and the new 1700's are six speeds. But this still comes up every once in a while and people claim the four speeds aren't geared for the highway. This may or may not be true. I'm putting this together in one place so everyone can see the truth.
The dual carb four speed VN1500's aka BUBF's had a top gear ratio of 0.965 until the A11 models(1997 I believe) then it was 0.781. The first of the VN1500 Classics(D1) were four speeds with a top gear of 0.781, too. Amazingly all the five speed Classics have the same top gear ratio of 0.781.
So the last of the BUBF's and all the Classics have the same top gear.
The interesting part is the five speeds went back to the gear ratio of the original four speeds for the first four gears with the newer top gear ratio.