Hey everyone new guy here!  Just got an 88 Samurai and loving it so far.  One thing right now that I really need to fix is the steering.  When its parked and just sitting there is about 1/4" of free movement in either direction and when I start driving upwards of 35 it starts to get pretty squirley.

Is there something right behind the wheel I can adjust or is it something under the car like a ball joint or something?

Any ways, here is a picture of it so you guys can get an idea of what I'm working with.

Check, or just replace, the rag joint (the rubber "donut" down by the steering box).  If it is torn, it will cause very loose steering.
There is nothing to come loose between the wheel and the steering shaft in the engine compartment.....other than the steering wheel itself.

Have someone rock the steering wheel back and forth while you
watch the steering parts under the truck, replace anything that
looks loose or is moving too much, and also there is a nut and screw
on the top of the steering box that can be adjusted to take out
some of the wear play in the box, but don't over tighten it or it
will be stiff to turn the steering wheel, just snug it up easy

Wild

Lookin good 

what about a blown seal on the bottom of the steering box, I had to have the stock pitman arm heated off when I did my SPOA lift and ever since then it looks wet there and I have had lose steering, also now my leaf springs have begun sagging below being flat (I don't know the proper term to call that but I have been calling it a negative arch, instead of the spring looking like a smile it looks like a frown) so it seems to shake more then it ever used to a few years ago.

Replace the seal, but that is the only problem, the heat won't cause the
steering to be loose,

Are you running stock springs? most stock springs look flat to neg arch, that's
just factory springs, if they were pos arch and have gone flat, it's a defective
part and should be replaced

Wild

Also, that length of lift shackle will change your castor angle and will cause the vehicle to "dart" back and forth more quickly. There are shims that go between the spring and the axle to correct this or better yet is to remove the shackles.

Hope that helps  -Eric

I like a bit of positive arch to my springs myself.  So I just added a second #2 spring from another set of springs as an add-a-leaf.  Later in the springs life I re-arched them to get the correct amount of arch for how I like my rig to sit. 

I am running stock springs still but when I did the lift (spring of 2000) they did have a positive arch but in the last few years they have flattened out and it has only been since then that the steering has gotten so loose

I would start with what wild and Sky suggested first.  Might be something as simple as a loose tie rod or sloppy tie rod ends.