Unlocked i4 Upgrade to 4.2

[JayMacApple]

I tried a search but couldn't find anything concrete. Sorry if this has already been beat to death....

I have an i4 unlocked/jailbroken running 4.0.1 with firmware 01.59.00...is there a way to upgrade with out updating the firmware and not have a tethered jailbreak? If so, can you point me in the right direction or maybe a tutorial?

I live in Costa Rica so having it unlocked/jailbroken is a must for me.

Thanks a bunch.

[ihappy]

The only untethered jailbreak at 4.2.1 requires a Mac, 4.2b3 shsh blobs and the 4.2b3 firmware. If you need an untethered JB then its probably best to create a cfw for 4.1 that will preserve your baseband for the unlock and update to that.