I used the Russell Quick Disconnect Fuel Fittings when I installed the fuel lines in my 5.3 swap. I recently started my PU and the preasure line came off when the pump preasured up. The plastic retainer clip stayed on the fuel rail and the fitting came off spraying fuel all over my engine. Luckily, my engine was cold. If this had happened while I was driving, it could have caught fire. At first I thought the fitting just wasn't seated correctly and re-installed it. It re-installed fine and re-seated correctly and has not come off since but I added a zip-tie to ensure it doesn't come off. I was going to just replace the preasure fitting with a new one and when I checked the LS1 website, I came across a post listing this same problem. It appears this is becoming a common occurance with mostly the preasure side Russell quick Disconnect fitting. Here is a link to that post
http://www.ls1tech.com/forums/conver...-fittings.html
As the link states, Russell has a new style fitting that will not come off. The fitting part numbers are 644120 (Summit #RUS644120) for the 3/8 preasure side and 644110 (Summit #RUS644110) for the 5/16 return line.
I called Summit and they did not have the part numbers in their system. They called Edelbrock and got the part numbers and they are in their computer system now but not on their internet catalog. I ordered both fittings and will replace the ones I have on now when the new ones come in, they were on back order and should be here in about a week. Here is a photo of the new fitting.