Just to reiterate what many people have stated. Yes iOS 4 is definitely not for the 3G. It literally look 6-10 seconds just to open "Settings" and another 2-3 seconds for each tap. It is possible if you guys want to know.
Follow this guide:
http://www.ihackintosh.com/2010/04/downgrade-iphone-3g-os-4-0-to-3-1-3-or-lower/
And it works!
On 3.1.3 with 5.13.04 Baseband.
Follow this guide:
http://www.ihackintosh.com/2010/04/downgrade-iphone-3g-os-4-0-to-3-1-3-or-lower/
And it works!
On 3.1.3 with 5.13.04 Baseband.