The spine charts are NOT correct for adding weight to the front of the arrow - which is the only way to increase FOC.
If you haven't changed anything yet, here is what I suggest.
1. Keep your Thunderheads
2. Search the web for 175 grain FP's. Your current insert is most likely 25 grains. So total point weight is 200.
Eastman's rules don't allow for redirects, you'll find most of the heavier points on traditional websites, thats all I'll say there.
3. They will shoot like darts and FOC will be around 16%. Penetration like a howitzer, arrow flight / consistency like magic. It's really great.
4. Buy brass 100 grain inserts for your hunting arrows and shoot Thunderheads. If you change all your arrows to brass inserts, you shoot 100 grain FP's. The 175's are only test points when you use standard inserts (Aluminum).
Again, the charts are wrong when you push only point weight up, which is the only way to increase FOC, FOC = magical arrow consistency.