Which is stronger

That's an easy choice for me. 8.75. Why? because it takes about 90 minutes to swap out the chunk if you want to try a different ratio, and you can sell whatever chunks you have grown out of.
It will take you longer to change the C&P in your 9.25;and just try and sell your used C&P set.

Oh shoot, I'm in the racer's forum again. Sorry. Just ignore me.