I don't see why you're so obsess with overclocking over 3.6ghz. After 3.4ghz, it's not worth the extra heat. It'll only give like 5FPS more, but if you get a quad and overclock to 3.2ghz, it'd give similar performance. The biggest mistake most people make is basing their performance at ghz only, they NEVER consider the architecture. The Pentium D was overtaken by the Athlon 64x2, then it was overtaken by the Core 2 line. Even if it's at 2ghz, it's still more powerful than the Pentium D, due to architecture and a unified L2 cache.
Edit: Here's a thread that supports my statement, where the 805 is obsolete, compared to the e8400(and 7500 too, since it's basically the same, but with 3mb of cache turned off)
http://www.hardforum.com/showthread.php?t=1293134