Question: I'm trying to install a deadbolt on our front door that currently only has a locking handle. All of the things I've read online are for doors that are up to 1 3/4 inches thick, but my door is 2 inches thick. 

Will there be any difference besides possibly needing longer screws to get the two halves to meet?

Answer: 
No, actually, the locking rod is made to snap off at various lengths, to make up for varying door thicknesses.

Make sure to center the bolt itself on the door edge. Disregard the factory template, as it will be based on a different door thickness.
Some locks need more than longer screws because the two sides fit into each other so they don't twist and become misaligned. Also, some use special barrel shaped bolts that are threaded on the inside and the outside and you're not going to find "longer" versions of those ("mounting screws" in the diagram).

I made doors for an outside shed that were a little over 2" thick and I decided I couldn't find a deadbolt that would mount securely enough to be happy with, so I opted for a different locking mechanism.

If you find the right deadbolt, longer screws might work, but you'll have to look at how the two halves come together carefully.

[![enter image description here](https://i.stack.imgur.com/rcv8U.jpg)](https://i.stack.imgur.com/rcv8U.jpg)