Well, I'm not in Colorado. Old vehicle titles tied to engine IDs are fairly common here in Texas. Most times when you transfer one like that these days down here - if you're aware of the fact that the engine ID is on the title instead of the body s/n, all you have to do is let the title office know about it and provide them with the correct information and they'll change it on the new title.
And on top of all that - the title I have does in fact match the s/n on the engine block - so it is verifiable to any registering authority.
