This proves you know nothing about iPhone hardware. There are exactly two parts shared between the 3G and 3GS--the case and the home button. New processor (Samsung 1176JZ @412Mhz vs. Cortex A8 @600Mhz), new GPU (PowerVR MBX Lite vs. PowerVR SGX535), new camera (2MP fixed-focus vs. 3MP autofocus), new glass (oleophobic), double the RAM, new audio circuitry (Wolfson WM6180C vs. Cirrus Logic CS42L61), larger battery. Even the screens are subtly different.
The 3G was identical to the original iPhone, with the exception of the case, battery, and radio/GPS module. Same processor, same GPU, same camera, same amount of RAM.