just look in your avalon..... as you unplug... plug into your new PSU the cables you need
as i peer into the avalon at the psu, i see 2 pci-e molex cables plugged into slots labelled "GPU". as you can see from my pic, there are no "GPU" slots. where would i plug the cords into the Seasonic?
= PCI-e
you did say in your own question that they were pci-e cables......
edit: i would actually replace the cables inside the avalon for the ones that came with your PSU, don't just plug the cables intot he new psu