FE is the name of the engine series believed to stand for Ford Engine. Some will disagree with this but Ford never really named the series but referred to it as only "FE" in factory documents and blueprints so who really knows anyway. If you do some shopping you can find good deals on parts for your 390. Sure they are a little more on some items because they are a lost breed of engine and the aftermarket is responding nicely with new component packages and improved parts. What I mean by lost breed is the engines are no longer produced by Ford only some aftermarket part sources and what you can find used or NOS. Thats why you pay more. I'd take a good look to see what it needs first and go from there. What year truck??? G.