I generally find goldtip's chart to be a bit too flexible for today's super speed bows. It actually usually SAYS THAT on the box of arrows. I tend to look at hunter's friend'schart (based on the Easton chart that literally everyone else's chart is based on), then make some evaluations based on cam design, draw length, and bow speed.
Based on your inputs and the hf chart, I would personally go with a .300" spine. The .340 pops right in the middle of the range, but that would be based on a 280-300fps softer cam bow, which neither is true for the Spyder Turbo. In general, if a bow is faster than 300fps I bump up a step, if it's a an aggressive cam like the cam and 1/2, I go up for that as well, which basically puts your bow either at the ragged edge of a .330" to a .300 spine.
I'd always rather shoot a stiffer arrow than I need over having a soggy noodle flying out of my bow because the spine charts weren't accurate for my specific bow.
(For the record, I run a bow tech destroyer 350 and a Mathews Monster, and I had issues with weak spine in both of these bows when I went with goldtip's recommended shafts. Stepped up one level and my flight was much improved. I'd classify your turbo in the same realm as these two bows in terms of punishment delivered to your arrows!)