910 D2 Fitting Help

I have a 910 D2 10.5 head that I recently was fitted with a custom shaft. I'm 63 and a higher handicap and was fitted into a 44" Oban Devotion 7, 75g stiff shaft which reduced my spin and gave me 20y more on average. This setup has a c9 swingweight and I'm experimenting around with changes. I went to a 25g grip to lighten the static weight and get a little more swing weight. This hasn't seemed to help my consistency and I'm thinking about increasing the weight in the head and or going back to a standard weight grip. It currently has the standard weight and what can I increase the swingweight to with heavier head weights?

How do I buy a heavier weight?

Also where is the sweet spot on the face and what tee/ball height works best? I heard with the newer heads it is no longer good to go with teeing it higher.

Thanks

There is a swingweight kit for the 910 metalwoods and it comes with 5 different weights so you can play with the swingweight.  You can purchase that kit at any pro shop and if they don't have it in stock, they can order it for you. 

 If you are looking to just change your swingweight, we would recommend that you go back to your fitter and talk to them about your swingweight and what you would like to achieve.  The sweet spot is in the middle.  If you hit it below the middle, you are likely to generate more spin and if you hit it very slightly above the center, you could get less spin.