Replying to Which full tilt model?

Right now I have the TW Pros and the flex is a 6/90, They’re a year old and I feel like I’m starting to leak out of the boot when I’m going down fast and steep. I know they aren’t made for that but last year they were doing fine. So now I’m looking for a stiffer model that’s good for glades and speed while also being solid in the park. I’m thinking about the first chair 8’s or the 10’s. Anyone know if there’s a massive difference in flex between the two? Which one would be the better move? Or should I be looking at a different model? Thanks