Originally Posted by
mattwoodcraft
i think you will find that he was saying to put the extra shim under the head button
Adding shims under the head button would only effect the compression ratio.
I think 22Racer was refering to a shim under the sleeve itself, which has an effect on the timing and hence the power band. Sounds like a great concept for guys with stock 5 ports in their buggies that don't want the expense of getting a full mod done to tame the bottom and extend the top.
Maybe Rex could explain further ??