First time installed MII. Some advice needed.

It will probably be covered in your instructions, especially since it's a bolt in, but establishing a reference point on your frame behind where the mods take place is very important, I think. Then you can take accurate straight and cross measurments before(so you know how square the frame is) and after( to make sure it stays square) If removing the front crossmember is required, most people would recommend welding or bolting in a cross brace on the frame to maintain straight and square.(this can also serve as your measuring reference) It's not as critical on a bolt in since you avoid the heat of welding. Welding can make frames do crazy stuff if you're not carefull. Also, get a magnetic angle finder and use a good level to insure it's all level on jack stands, or such, before you start. Use the angle gauge often on each side of the frame before and after you drill/bolt, to make sure everything stays square/parallel. It's also a good cross check on your level. You CAN'T measure too much.