Ports question

[mattloaf1]

I'm pretty familiar with the concept of ports and how they work, but I am kind of confused on something.

I'm behind a firewall that only allows inbound traffic on certain ports, one of which of course would be 80, for http traffic.

I use Bittorrent, and have no problem downloading, but I can't upload very well, I'm guessing because connections needs to be established in that 6881-6889 range. If I change the Bittorrent port to 80, shouldn't my connections work fine, or are the clients on other people's computers looking for ports 6881-6889?

 

[mattloaf1]

Now that I think about it, I think the problem might be with port forwarding and not the actual port I am using. But if I tell the router to send all port 80 traffic to my machine, I don't think anyone else will be able to use that port for web stuff. So I guess I should just find another open port, forward it to my machine, and I'll be able to seed through that number, no matter what port it is, as long as it is open?! Thanks for your help in advance.