Hi all, We have a GMC 01 Lb7 that we just replaced the head gaskets. due to the gaskets failing and leaking coolant out of the heads to the out side. The truck is new to us so not sure why the gaskets failed in this way. We did all the normal head gasket checks before we got it. After putting everything back together and starting the motor we have a fuel leak from the rear of the driver's side head. It looks like it's coming from the banjo bolt area of the external return line. The line was brand new from Merchant automotive with a new copper washer assembly from the dealer. It's hard to see with a camera. It's not leaking from any other fuel parts on top of the motor on that side. We even removed the return line to see if any cracks and all looks ok. We would greatly appreciate any insight on this. The injectors were already replaced by a shop way before we got the truck (we have the paperwork) sorry for the long write up just trying to give all the details.