Crankset for 2011 Specialized

[Speeltyd]

I recently bought a 2011 Specialized S-Works Epic with XO groupset. When I look at its original spec, it came out with SRAM XX. I am now changing it back to the original and have done the deraileurs. However, the 2nd hand crankset I bought, does not fit. It's specs are XX, BB30, 175mm, Q Factor 164. This last spec is where the problem is. The Q should be 168. But there is no XX available with Q 168. Where am I wrong, or what am I missing? Forgot to add- 2x10, so no XX1