How do you upgrade to the latest "unlockable firmware" for 3G 3.1.3?

[o5va1d0]

Hello everyone,

I'm new to here and I just wanted to know what was the best way to upgrade my iPhone 3G to the latest unlockable firmware.Its FW is 3.1.2 and BB 5.11.07. It seems that most of the apps that i like or that i want to download only work with 4.0+. Can anyone give me the step-by-step guide on how to do this? Thanks in advance for your replies.

[tito12]

You should use a custom 4.2.1 firmware in order to keep your baseband. You'll probably come to the conclusion that 4.x fw are too heavy for 3G like I did.
Good luck!

[o5va1d0]

By too heavy do you mean it'll run slower?

[Mes]

Yes ... and it will be noticeable.
The ..only.. half-way acceptable method to run 4.2.1 on a 3G is with very very few tweaks.

[o5va1d0]

isnt there a patch or something that helps it run faster and fixes the battery drain?

[Mes]

Likely the 'patch' you're thinking about, disables multitasking, wallpaper, and other memory consuming apps.
I use Springtomize for the same thing, plus disable Spotlight and most other 4.x features. Once disabled, 4.2.1 works so so.