Ill be running in VTA class with an Xray T3. Do I need the fan and heat sick is a question I can't answer yet, just finished building the car. I have seen a lot of guys at the club run fans to keep that 25.5 cool. What I liked about the heat sink that Novak made is that it just took place of the aluminum ring and added the benefit of cooling fins. It also allows you to mount a small fan on it. I have plenty of space facing the back of the car.
If anyone has one of these older heat sinks on their velocity motor, I would love to make you an offer to buy it from you if you're not using it.