1995 454 Exhaust Leak

[Blazer Eagle]

Last June I had the donut gaskets replaced on my 95 454. All stock as far as the exhaust is concerned. This fixed most of the exhaust noise I was hearing, but there was still that annoying exhaust leak tick tick tick under the floor board. I assumed that meant I had a cracked manifold.

Fast forward a few months and 12k miles to now. The exhaust leak is back with a vengeance. It's so bad I have to shut the truck off to order from a drive through. I had chance this weekend to poke around for the cause and found that the donut gasket on the driver side is blown out again.
I also found, a crack in the manifold as expected - what I didn't expect to find was a sheared off bolt.

What would cause a donut gasket to blow out so soon?
Can the broken bolt be extracted without pulling the head?
The passenger manifold has a small crack too, if I replace both manifolds should I go the extra mile for headers?

Thanks for all your help, I'm just trying to decide what the best route to go is

 

[RichLo]

Headers are defiantly screaming your name right now.

and yes, you can remove a sheared off header bolt without removing the head, its pretty common practice but its still a PITA. Just take your time and buy the right tools for the job.

 

[long_bed]

Clogged cats or bad motor mounts?

 

[Blazer Eagle]

So let's say I pull the manifolds, pull the broken studs out and install headers. How do I get the truck to an exhaust shop to sort out the rest of the exhaust? Do I tow it, or is there some kind of bolt on temporary solution?

The cat is only 2 or 3 years old, but it could very well be clogged. Don't they usually heat up and discolor real bad when they clog?

I would guess the motor mounts aren't in the best condition. The truck has 400k miles. The engine was rebuilt at 300k but I doubt the motor mounts were replaced.

 

[House003]

I would just drive it without the rest of the exhaust with ear plug in lol

 

[Ironhead]

So let's say I pull the manifolds, pull the broken studs out and install headers. How do I get the truck to an exhaust shop to sort out the rest of the exhaust? Do I tow it, or is there some kind of bolt on temporary solution?

...

Drive it, but do NOT step hard on the loud pedal if the cops are anywhere nearby!

 

[Blazer Eagle]

Well here is a crappy video of me revving the engine. I'm only giving it a bit of throttle, revving it to about 3k. If you watch the alternator you can see movement - I'm just not sure if that is too much movement?

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Here's a shot of the truck for the hell of it

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