When I did my 5.3 swap, I used the Russell Quick Disconnect Fuel Fittings for my fuel lines. Shortly after I started driving it, I started my PU and the preasure line on the fuel rail 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 did not come back off but I added a zip tie to ensure it didn'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.
Here is a photo of the new fitting. The C clip screws into the fitting on the back side of the bulge in the line and this fitting will not come off. I would recommend anyone doing this swap use the new fittings instead of the old ones with the plastic clips. They are basically the same price. The fittings may not be on the internet or catalog yet but I was able to order them using the part numbers. Just a little Fire Insurance.