i want to change my 97 ultra to a long track but a dealer said i have to get new drive sprockets. i have four and he said i need two. i thought all tracks were the same on the inside. so what should i do?

if you are going to a deeper lug track, 1" to a 2", you need to change the drivers to smaller one's. the 2" track will not clear the cooler, the smaller drivers will alow this. ( 9 tooth to 7 tooth). as for how many to install, you need two drivers and two careirs. GOOD LUCK