I run the 2" Marlin spacers on each corner. 

My personal way of doing it was this...........


Use RED locktite.

I didnt torgue anything.

I used a 4 way and tightened the studs to the axles till it didnt budge anymore

then I tightened the wheels to the spacers in the same fashion.

I have checked em twice and could only budge a couple of the nuts out of all of them but just barely at that.

I think your biggest factor is if you are running aluminum wheels on the Marlin aluminum spacers, aluminum is soft and will settle a bit more.

My wheels are steel so mayber that is why I have had no problems.

I'm going to be running steel rims for sure, already got them, and I'll be sure to clean off the flange well before putting the spacers on.

How did your 5" extreme lift go?  I'm working on mine now and have had a few issues like the front shock hoops, the steering arms and a few other things.

I haven't had the nerve to put them on again.  I'll be doing the IFS hub swap to avoid having that spacer between the rim and flange.

Word of caution and this was probably a contributing factor was I did not clean the hub surface. Sand any rust or crud on the hub off so that it will get a good clean surface to seat on.

Holy crap!  I bet the recipient of that tire was flipping out!  What is the IFS hub swap as that is a new one to me?

As I stated above, I'll probably clean the hub surface real well and check the bolts/nuts frequently for a while until the spacers get seated.