Just a quickie before I hit the upgrade buttons ;)
I have an untethered 3GS from the first few weeks still on the 4x baseband. I want to upgrade the baseband and go to a 3.1.3 jailbreak as described here iClarified - iPhone - How to Jailbreak Your iPhone 3GS Using PwnageTool [Mac]
My iPhone is carrier unlocked so I'd like to get baseband up to it's latest. How do I do this? I have SHSH's only for 3.0.1 (which is my current FW).