Well you know I'm running the 9f and I got to say its a torque monster and I'm running on 10.8:1 maybe slightly higher. Since my setup is void of any pinging I think the 11.1:1 that your running would be much more fun. The woods in my opinion is a better fit than the 640 S&S. The reason I say this is that besides the higher lift it also has less duration. S&S has 265 and the woods is 256. And we know that more duration means more compression so at 11.1:1 this would be fun. But here's the question that you have already asked yourself, would it be noticeable from where your at right now? Will you have to replace your springs? How about piston to valve clearance? Its winter I say do it. I will be available today should you need any further justification or help in spending your money.