Mark, there are seniors with fast swings and slow swings, quick or rhythmic tempo, driver heads that are low lofted and high lofted, shafts with high kick and low kick, an almost infinite number of combinations and hundreds of shafts available. The point being, your best option would be to go to a certified fitter. Even if you don't buy a new completed driver you will come away with a better idea of what to look for in a shaft that fits you and the driver you pick.

To Dale's point, based solely on swing speed, I should be using the Kuro Kage shaft. In order to get optimal distance, we tried 10.5 with the KK and 11.5 with the Tensai Blue. 11.5 with the KK launched too high. Trackman voted for the 11.5 with the Tensai Blue for spin and descent. Off the shelf or empiric ordering is no place for a senior player.

I was fit 2 years ago age 62. Wasn't best day of swinging (never is), but results were:

917 D3 10.5* 10 gram weight
Mitsubishi Rayon Diamana LTD Red 50
Golf Pride CP2

Been very satisfied. I go for consistency first priority over distance at the moment. Suggest you look at the shaft guide to see what kind of ball flight you want or Titleist Fitting day (heard the TS is awesome by everyone who's swinging it).

Good luck