Is my RAM holding me back?

I'm using the following components:

Intel Q9550
Gigabyte GA-EP45-UD3P
2x2GB Mushkin DDR2 800

When I finished building the system, I didn't know much about overclocking and fiddling with things in the BIOS. Instead, I used a feature in Gigabyte's EasyTune6 called QuickBoost, which offers 3 incremental levels of overclocking. On my hardware, these are the 3 levels:

8x400 MHz FSB (3.20 GHz)
8x430 MHz FSB (3.44 GHz)
8x450 MHz FSB (3.60 GHz)

So, I decided to give the 430 MHz FSB a shot. What I didn't understand at the time was the link between the FSB and memory speed. After reading the stickied posts here and other guides about overclocking, it's now clear to me that running with the 430 MHz FSB is overclocking the memory at 860 MHz. Additionally, EasyTune6 also tweaks voltages - I discovered it had bumped DRAM voltage to 2.0V. According to the specifications the RAM is rated at 1.8V. I did not find any instability in when using the computer for "normal" tasks or Prime95 tests. Is there any risk I run to overclocking and overvolting the RAM like this even if it runs stably? If I want to push the FSB overclock to 450 or beyond should I look for faster RAM now?