Bicycle Mechanics - Rear Cassette Installation

I am going to upgrade my rear cassette from a 11 - 23 cassette to a 13 - 27. My question is ... will I have to do any adjustments after the install? Cable?, Derailer? Etc.? I have read Sheldon Brown's site and the Park tool site and am very comfortable in changing out the cassette but I am not sure if I will need to make any adjustments as both sites are silent on this issue. I plan on riding a metric century this coming weekend and I'm not real interested in screwing up my ride the week prior so I have nothing but problems.

Any input would be appreciated. Thanks in advance for your help.

Loosen your cable and Check your RD alignment stops on the small and large gear. Then reset your cable tension and it should be OK.

If all you do is change the cassette, you should not have to change anything. The cassettes are a precision part they are all spaced the same, as long as the cog count is the same(8 to 8, 9 to 9).
The big issue is that you are going to a much bigger low gear. With the rear on a small cog, shift to the big ring in the front. Gently shift up in the back, (Do this in a stand or with someone holding the bike up, not while riding) watching how tight the der. gets. You want to make sure the der does nto go full tight before you get to the big gear. If it does you either need a longer chain or to be very careful when down shifting in the rear while in the big ring.
It would not to check the shifting while doing this to be sure it is ok, and once you are on the big cog, give it a nudge with your hand to make sure the stop screw is adjusted properly.

Thanks for the info. I did end up backing off the "L" adjuster, along with the cable. I found that the derailer wasn't allowing the chain to fully engage the big gear. All seems fine inside and hopefully the rain holds off tomorrow so I can go for a ride to check it out. Again thanks for the input.