Upgrading iPhone 3GS from 3.1.3 to 4.3.3

[arihantj]

Hi guys...

Im a newbie... and im just unsure on how to do this.. I wanna jailbreak my iPhone and unlock it as well... Currently im using iOS 3.1.3 which is jailbroken...

So is there a way to upgrade it to 4.3.3 jailbroken and then unlock it...?

Thanks

[Kenny1921]

In my little knowledge, no. you need things called SHSH blobs which you can only get from jailbreaking the firmware so there for you would need to have had and jailbroke iOS 4.3.3. iTunes will only let you update to the current firmware which is 4.3.5

If you have got SHSH blobs for iOS 4.3.3 then there shouldn't be a problem providing you have a device that takes the 4.3.3 firmware as the iPhone 3G can only update to 4.2.1

[iYeow]

If you have 4.3.3 shsh blob, what you need is to restore to custom firmware of 4.3.3. So do you have the blob ?
Run tiny umbrella, plug iphone in and click save shsh. If you don't have it , then you can only restore to custom firmware of 4.1

[jinthec]

Make sure and read All the dev teams and iclarifieds jailbreaking guides, you need to preserve your baseband, 4.3.3's baseband is not unlockable, unlockable basebands stop at 5.13. I blew it and upgraded to 4.3.1 and now have baseband 5.16 which is unlockable and no way to downgrade the baseband.