I have a 9" throw at the stock tie-rod mounts (those arms are about 8" long)
You have to measure the length of the steer-arms (center to TRE) that you are going to use, since it can vary a bit from different manufacturers.
If they have reverse hi-steer, it's probably about 6", which will give you a throw of about 6.75".
If you use conventional hi-steer, the arm is probably not more than about 4",
which will give you a 4,5" throw.
(All this assumes that you connect the ram-assist to the tie-rod)
But you don't have to limit the throw, just use one that is longer than needed.
What is more important is that you need a larger diameter when you use a shorter arm.
A 4" arm needs twice the ram-area as a 8" arm.
But keep in mind that the limiting bolts can be differently adjusted, and arm-lengths can vary, so you really need to measure the throw on your own truck
English isn't my first language, so I hope this made some sense.