I installed my new shackles and when I tightened them down they started to bend in a little so I loosened them and just got them tight enough to hold. I haven't driven it yet but I was just wanting to make sure it's OK before I drive it.

Fine as Frog Hair Split 4 Ways....... 

That's how i have always done mine. I use nylocks and check them occasionally though.

Well I've driven it about 30mi +/- and they seem to be holding up. I like how much clearance I gained off a 1.5" shackle lift. It really did a lot for stance too. Clears my little 28" tires and then some but they fill it up and makes it look like I'm running 31s haha

I just installed shackles too!   Never done any suspension mods but it pretty basic  ..  I bought new bushings and they have a sleeve that prevents over tightening.    My shackles were homemade and 1 1/4 longer than stock this picked me up off the bumpstops and leveled off the vehicle.   I just installed 225 75 15s as well  I am happy   It gives me very minor changes  and a better ride.  No noticible differance in gearing.   The Rims and Tires were loaned to me. so  I spent only a very small amount of money and I get to try it out  for a while to decide.   I think this might be as far as I want to take it, because I dont want to put say 31s on here and need to cut this and that   put springs and then Ill need  gears stronger axcell  or bigger motor. 
    Any way if You dont have a sleeve you need a nylon loch  or perhaps a nut with a locking cotterpin.  because you cant make them tight or you will bend the shackel

I used GRADE 8 nuts and bolts, on the top bolt I used a lock washer and a self locking nut, on the bottom bolt I just went with the lock washer and a regular nut. It's all grade 8 so I know that the bolts will at least hold up