Ahh, OK, got it.
If you're only selling into that single US market, then customs information for US customers on your site would be a good idea I think. Keeping your customers well informed through your website can only be a positive thing, but you just have to always be aware of keeping your information sectioned.
For example, information such as that should go under the "Shipping Category". You wouldn't want to just cram everything under something like "About Us" like many do. All that does is make a site messy and makes it hard for a customer to find details on the relevant info they are looking for.
Having a clean and concise website design is like being served by a clean and concise sales consultant in a bricks and mortar store. When you ask a question, you want a good straight to the point response, you don't want a sales rep that waffles on about nothing before getting to the point. No different to online, customers want the information they are looking for as quickly and concise as possible.