There are several Crosshairs in the Aslain Modpack that have lead indicators. They are listed in the Crosshair Mods section
When installing Aslain Modpack, check the box to show previews, in the Crosshair Mods section, click on each Crosshair and it will show you an example in the preview window
A few that have lead lines you are looking for:
Tiapan2
Warplanes Classic
Kellerman Blue
Destroyer Green or Green
Protanki
Standard in white
Sniper
Melty
Staple
Devastator
Animated
Strv
Aslain thought you were asking for an "Auto Aim" like "Ogre Ninja" that will automatically lead a moving target and aim for weak spots; those kind of mods are illegal and will get you banned and none are included in the Aslain Modpack