You can configure the same via virtual host in httdp.conf with redirection rule or you can do the same with ELB in which you can mention the request comes on 80 and ELB will forward the same on 8000 port.
solved My AWS ec2 instance is running on ec2-xx-1xx-xxx-24.compute-1.amazonaws.com:8000. how do i make it run on ec2-xx-1xx-xxx-24.compute-1.amazonaws.com