I know the numbers on the shaft say 7595, but unless one of the other guys correct me I would not recommend them. I've never gotten real technical with them but everything I've read says the 7595 is a 340 spine, which is basically what you are now shooting. Even GT's website lists them as a .340 spine.

Maybe TFox can run the numbers.

In the Gold Tip line you can shoot the Ultralite 300 or the 22 series shafts, which are also a 300 spine. Both are light weight, so this might not suit your application. There are other ways of increasing the arrows' weight though. Another option GT has, if you're interested is their CAA shaft (carbon aluminum arrow). These are real close in specs and quality to Easton ACC's without the heavy price tag. Might be a good balance between speed and weight for penetration.

Just out of curiosity, when you dropped the weight on the bow just how much closer were the bare shafts hitting to field points?