1993 bonneville, not supercharged. Had a hell of a time removing the three nuts securing the throttle body to the plastic plenum. Not much to grab onto on the bolt side. I did get them off, with a lot of TLC. Were they corroded, or did GM use loctite when it was assembled? Can I reassemble with neverseize or do I need to use loctite?
Has anyone ever replaced these with a standard nut and bolt, so a wrench could get on the back side? The factory bolt is a type of shoulder bolt, I could make sleeves at work and use a standard bolt, anyone have thoughts on this?? Thanks.. Mike.

Mike, the L27 is known to be a little PITA for this. I personally would never (and have never) used loctite on L27'*, and I've been through the top end of 3 of them. If the stud binds too well to the threaded anchor, it may break the anchor loose and cause it to spin when you try to remove it. I suggest cleaning the back (hex) side of the anchors very well with a degreaser, then flush with rubbing alcohol and using a very strong epoxy like JB weld to bind it in place very well. It may help to rough up the surface of the the intake and stud anchor with 60-grit first to help promote adhesion.

Put a small piece of tape over the hole in the anchor first so the epoxy doesn't get inside the threads.

Now after doing this, the next time you go to remove the nuts/studs, the anchor will never be able to break loose and spin. This has happened in the past with others, including myself on a friend'* car. It never fails, it'* always that pesky lower stud on the rear side closer to the firewall that you can't really get a wrench on to back it up.

Okay, so it was just corrosion... And yes, the entire thing spun in the plastic plenum. And luckily, had the whole thing on the bench, so I did get it out eventually without any damage. I thught about using expoxy when pressing it back into the plastic, then using anti-seize on those little nuts for the future removal. I just wanted to be sure that there was not a concern of these nuts backing out, and therefore they were locktited.
Have you ever pressed a bushing into the plenum, then using a 5/16 nut and bolt instead of this factory nut and should bolt? It should work, and I can get a bronze bushing of proper size for less than a buck per... Do you see any reason why I can't do this?

Thanks, Mike

The anchor in the plenum is quite large in surface area to distribute the load and not stress the Nylon (black plastic). I think you could do just about anything you wanted to as long as you took this into account.

Anti-seize should work ok. Especially if you use a jam-nut as well.

Thanks Willwren, onward and forward I go....

Mike