Working on a 1953 6400 with a 235. Went to remove the lead pipe. Normally I'd split the nut to get it off. Not sure what I am looking at but does not appear to be a nut. Could be a hex shaped spacer with a 5/16 bolt (head is 1/2" not 9/16 but spacer or whatever it is is 9/16) threaded into the manifold or some type of JC Whitney latest and greatest exhaust fastener fix. Anyone know what I am looking at. Obviously don't want to break off in the manifold.
Having technical difficulties tonight will post pic in the morning.
From your picture it looks like a bolt head and not a nut as you would expect. There are two possibilities. Either the PO drilled out the original stud due to it being snapped off and used a nut and bolt in place of the stud and nut or they were able to unscrew the worn stud and used a bolt in place of the stud.
If it is a bolt screwed into the original threads you best soak it with PB Blaster or Kroil for several days before trying to remove them. Even then it may be necessary to heat the area around the threaded section with an O&A torch to get them to move. If you can get them to move, don’t try to muscle them out, but instead finesse them out by soaking, tightening, loosening a little at a time and repeat.
This is what it should look like.
Last edited by Phak1; Thu Sep 17 2020 01:17 PM.
1952 Chevrolet 3100 Project Journals ‘59 235 & hydraulic lifters “Three on the Tree” & 4:11 torque tube 12v w/ Alternator