AMD X2-4400 OC'd Temperature Question

I have an AMD X2-4400 running at 2.6 GHZ. I have an Antec case with 2 80 mm case fans and a Thermaltake XP-120 and 120mm Stealth fan cooling my processor. Arctic Silver 5 was used as the heatsink interface. Cable management is fair so air-flow is not overly restricted. Voltage had to be bumped up to 1.4125 in order to have a stable system.

There is also a WD Raptor (just one) and a single 7800 GTX (running at 450) in the case creating a little more heat.

In a very cool room (approximately 18C) my processor idles around 38-40C and when I execute two instances of CPU Burn-in (I have to run two since the processor is dual-core) it warms up to 54-56C. Is this normal? I realize every system is unique, but I'd just like some opinions on this.