Look, I know this may seem like a good idea now, but the best thing to do really is to just add the second drive to your system. Unless you know you really want EVERY FILE on there the better solution would be is to link up both drives to your system and as you find you want to use a file on the old drive, move it to your new drive. Hard drives these days get so cluttered with crap that even though there is a lot on there that you want/need. You will still be putting a lot of extra junk onto your fast shiny new drive and you will also be using up more unneeded space. This is why cloning can be very inefficient. This will also save you a lot of headache as you won't have to deal with all of this cloning nonsense, and you will be able to put all of your files you ACTUALLY want onto your new drive gradually. Then in the far future as you have done this same thing with many drives and the original old drive starts to die, you can toss that old drive out. I like to think of this a a good, reliable way to "filter" your data over the years. At first when you put in your new drive with your old one, just start initially putting in all of the basic programs that and files that you know you want in your system and then start to trickle the remaining data in as you find you need it.
(pick best answer if this was helpful..I really need it <(^^)> )