Here is what is written:
1969-1973, F-4J: In the late 1960s, two situations resulted in the F11F finally being replaced. First, the Navy was running out of F11Fs. Second, the Navy had bought an improved version of its front line fighter, the McDonnell F-4 Phantom, but its new radar and improved engine were not available in time to be installed in the first production F-4Js. As a result, the Navy had brand-new Phantoms with lead ballast in the nose and the prior version of the J79 engine. Twelve or so of these were made available to the Blues to replace the F11F. To improve handling qualities in the very close formation maneuvers, the control system was modified, including a change to allow afterburner to be selected at a lower engine rpm. A smoke system was also added.
Although the Phantom was a terrific air show airplane, the Blues experienced a series of unfortunate events with them. Nine of the lead-nosed Js were lost in accidents between September 1969 and March 1973, requiring replacement with a few “real” Js with the J79-GE-10 engine. Another was destroyed in early July 1973 at an air show. However, the 1973 season ended in tragedy on 26 July when a midair between the team leader and a wing man occurred during an arrival display at NAS Lakehurst NJ. The boss, the pilot of the other F-4, and a Chief Petty Office in the backseat of one of the F-4s were killed.