What mods to go from 4.5" lift to 6.5"?

[Mudderoy]

What do you have to do to go from a 4.5" lift to a 6.5" lift.

Things that come to mind are:

6.5" coil springs or 2" spacers
2" shackles
longer brake lines
SYE
longer shocks.

What about the front end parts, like drop pitman arm. Is that enough to fix the geometry?

[4.3LXJ]

The first thing is that I am not a fan of shackles. They will make your leaf springs go flat eventually. You can ask Muddeprived about that. I would choose spacer blocks over shackles. Shocks of course.

The front is the tricky part. If you don't have long arms now, you will need them or drop brackets. 6.5" is too much for short arms. Your current track bar may work. Droped pitman arm would be good with a steering box brace to take up the added torque on the bottom of the box. If you do that, you will need a track bar drop bracket also so you won't get bump steer. Longer shocks of course. Personally, I think that longer springs are preferable to spacers if you are going to all that effort. You might need brake lines also.