The issue with spacers is when the studs are over torqued, they are stretched and weakened. Tighter is not better. Tighten to spec with a calibrated torque wrench (I prefer name brand like my Matco) and use Loctite. You will never have a failure. I did mine at 90 ft/lbs, used a lot of loctite, and triple checked every lug before the loctite dried.

Another note: Some people recommend to re-torque after a few hundred or a few thousand miles. I don't agree with this; if you use red loctite, you would break the bond if you tried to re-torque. This is the same concept when building engines. The only bolts when building an engine that need re-torquing would be head steads with cast aluminum heads, since loctite is not used, gaskets compress, and cast aluminum may flex under heat. With a wheel spacer, the billet aluminum does not flex or change with heat.

If you want to double check after a few hundred or thousand miles, turn the torque wrench back 5 lbs and check every lug, this way you know its tight without breaking loose the loctite. My 2 cents.