Nuts and Studs for exhaust flange to manifold
 

They are universal fit, right? I have a 390 in my '65 Thunderbird, though the engine may be out of a full size Ford or Merc originally. A standard Thunderbird exhaust system fits works on the car.

Have a leak at the pass. side flange (donut), and the nut won't tighten, so it's probably the nut stripped, though it could be the stud. The H pipe and donut are new, so I doubt it's them as the cause of the leak.

If it is the stud (Though the old one doesn't looked stripped to my eye) I'm hoping I can get it out and replaced without removing the manifold or even the flange pipe. Looks to be enough clearance on the pass. side. Any tips on getting the old one out are appreciated.

I assume this kit will work? What's your preference, brass nuts or steel?

https://www.cjponyparts.com/amk-prod...SABEgJXdvD_BwE

Re: Nuts and Studs for exhaust flange to manifold
 

If you can get penetrating oil into the top of the stud (bored thru the exhaust manifold) that would be a start. But my best luck with rust frozen parts has been heat. An old time mechanic told me to just get it red and back off and let it cool. Repeat at least twice. He said it was the expansion and contraction that broke the rust loose.

I'm partial to brass nuts (no comments please) but the donut, and both seats have to be clean and in good shape to seal at the lower torque rating. But they don't rust up.

Re: Nuts and Studs for exhaust flange to manifold
 

Have been lucky with heat and never broken one "Yet", sometimes it sure puts up a fight and squealed in protest backing out.

Re: Nuts and Studs for exhaust flange to manifold
 

:D

Sorta like why Gypsies couldn't do the TWIST in the sixties ...

Re: Nuts and Studs for exhaust flange to manifold
 

At this point, it seems I have the problem acceptably resolved. I loosened the clamps at the H pipe to the pipes behind to give some slack, then snugged up the flange connection with new brass nuts from NAPA to get a fairly decent seal. Studs seem ok and thread-worthy. Only the faintest hint of an air pulse from the connection now and no noise at all from the connection that I can tell, so we'll drive it around for a while to make sure it's ok. I'm thinking the guy who put the donut in messed it up. He didn't do a great job in other respects.

Re: Nuts and Studs for exhaust flange to manifold
 

Some of those manifolds were prone to cracking, but since you got it to quiet down I doubt that is the case.