Stretched exhaust bolts on GMC exhaust manifold

[gadget73]

I think the M21 is a half dozen of whatever holds it on. With any luck, that isn't a piece of information I'm going to have to learn about.

 

[Mr Boochie]

I think the M21 is a half dozen of whatever holds it on. With any luck, that isn't a piece of information I'm going to have to learn about.

Hope so!

 

[Bratwurst7s]

1) Torque specs:
High end of the spec = clean and dry threads.
Low end of the spec = clean and oiled (etc) threads.

2) All bolts, nuts and screws are springs.

 

[gadget73]

2) All bolts, nuts and screws are springs.

until they are shear pins

 

[Charlie207]

I ditched the factory GM manifold bolts with studs and nuts when I swapped engines in my 2014 Yukon (5.3 > cammed 6.0). I reused the factory cast manifolds as they were still flat/had no leaks. Using the studs & nuts made it 100x easier to get the old manifolds out when I swapped in long-tube headers a year after the engine swap.

 

[GordonW]

Pardon Our Interruption

Those are what I guy I know used, when he built up his version of the Sloppy Mechanics "Don't BS Me" turbo 5.3 LS. He beat the crap out of that thing, and to my knowledge, never had any sort of exhaust leak.

When I say "beat the crap out of"- I mean repeated passes of 9.8 seconds and close to 150MPH in the quarter mile, and quite a lot of street shenanigans, with that engine crammed into an early 80s Fox-body Mustang. Running on E-85 probably made for less heat, but that's still a hard life for fasteners.

Regards,
Gordon.