I have a 3g 8g got my hands on a 16g logic board..Can i simply swap the logic board and turn my 8g into 16g? i know how to do it. just wanna make sure it will work
In theory, yes it will work at I've seen other people do it.
BUT I've seen 9 out of 10 people who do it have serious problems after, the main one being no service, and not being able to get service after a logic board swap. So be careful.
I personally would see if I couldn't get another phone to experiment with...off ebay perhaps. Messing with your only iPhone and not having a backup could spell disaster.