Overclocking RAM and Northbridge?

[Deadboy90]

Hello,
I have a Phenom II x4 B50 running smoothly at 3.7ghz @1.46 volts (Up from stock 3.2 @ 1.4 v) I have tried pushing it farther, but any setting above 3.74 ghz causes errors on the windows desktop and soon, a BSOD. It doesnt seem to matter how much voltage I give it, I went up to 1.5 v and tried 3.76 and BSOD'd. Can the wall I have hit be overcome by messing with my Northbridge and RAM? I have never overclocked either of those so can someone give me some tips?
Rest of my rig:
Asus m5A97 EVO
Crucial Ballistix 1600 mhz
Sapphire 6850
Samsung 470 128gb ssd
CPU cooler: Coolermaster Hyper 212 evo

 

[C12Friedman]

The biggest limiter I see is that you are trying to overclock a CPU that had a locked core. You will probably see greater gains trying to overclock as a three core (and have far more success I will predict). My thought here is that anything over 3.2 (stock) is good on four cores and 3.7 from a locked core (keep in mind that the core may have been locked because it couldn't pass standard binning) is probably near it's limits...
My $0.02 worth