The ASRock P67 Fatal1ty Professional Memory Support List shows only three memory kits using 8GB modules that are supported. Your memory kit is not in ASRocks list, but Crucial's memory finder recommends the kit that you have.
Can you borrow and try booting with one or two 4GB memory modules?
It's possible but unlikely that both of your memory modules are defective.
Can you borrow and test with another power supply?
The problem might be due to a bios version issue.
I think that the bios chip is located below the red memory slot, closest to the cpu.
There should be a label on the top of the chip that will tell you the bios version of the chip.
It might be an older bios version that doesn't support Ivy Bridge processors.
Your system might boot with a Sandy Bridge cpu installed if you have an older bios version.