Hi Norm, having a longer rear guide that fits the spring properly is the main part of the equation to reduce the twang. Be interesting to know how that existing "guide" is fixed in. Don't know if you can post pictures? Hopefully you'll be able to remove and substitute it for a custom, properly fitting guide. Or maybe use the existing "stump" as a base for the new guide?

Hope this helps and it'll be nice to hear how it turns out.