P4 423 really a P4 478?

[swidey]

Any one notice the massive similarities between a 423 and a 478 P4? I was looking at my unused 423 proc, and realized that inside of the pins, there are solder points for what appears to be a 478 proc. Also if you take away the pins around the core it would look just like a 478 proc. Maybe old 423 proc could be converted to 478's with some patience and a little solder?
I'll try to get pics to show you what i mean soon.