It's probably not a problem if you plan to run this service from your local machine and understand that it's the standard port for http requests, so will conflict with browsing. If a high volume of both http traffic and traffic to/from your service is required, you would avoid packet fragmentation and loss by choosing another port. The Internet Assigned Numbers Authority (IANA) offers a list of "standard" port assignments at [iana.org...]
Also, if I recall correctly, opening low numbered ports (less then port 1024?) requires root level access (on Unixish servers), at least to initially open the port. That could present a security risk, depending on tightness of code and goal of opening the port.