LCOS issues on some aircraft, how to fix?

[Icarus999 70]

I have noticed that certain aircraft certain aircraft such as the TW F-15A do not seem to have functional lead computing optical gun sights. while others like the F-15SE seem to work fairly well at maintaining boresight alignment.   For instance , when pulling g's in a dog fight in certain HUD equipped aircraft , the piper  will diverge radically from the boresight  of the weapon and burry itself  in the bottom of the Hud if I happen to be pulling up... or the opposite if I am in a dive.  The gunsight is actually fighting me rather than computing a lead solution. :)  

I have been comparing Avionics INI  Hud Data between aircraft and have tried some changes but to no avail.   Perhaps I am looking in the wrong place?

Need a little advice here.

Thank you