I run 2" wheel spacers from no other than Marlin. I also run 2.5" backspaced wheels with 37" MTR's. I use red loctite and have NEVER had an issue with mine coming loose. I wheel the hell outta my rig when I get to go and I have had my Runner over 70 mph. on many occasions and have never had an issue.
I will say though that if you gotta get em off, you may have to lay down the purse and put some muscle into it to get the nuts to break loose.