You can't just look at your 330 and think that makes the difference. Likewise, you can't sacrifice your run just to get a better 60'. It's all about the 1/4, so you need to do what gets you there the quickest. A 108 trap with a 1.67 60' should be a 12.4. My best time here at altitude is 12.30 @ 107.99 with a 1.72 60'. That's a little skewed for two reasons: 1) I'm at high altitude and shift to 5th before the 1000', and 2) I was trappin 109.xx on the other runs.
Yes, I powershift every gear, and I'd say it can help by a tenth or so if you're fast, but your current situation is not being caused by not powershifting. You just need to learn to speed shift and shift at the proper rpm.