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Discussion Starter #1
Hey guy's I'm tired of listening to the exhaust leaks on my 390 on the tops of #3 and #7 so I'm taking them off to get machined to see if that helps.I've got the passenger side off,but not out yet.I've got 4 bolts off the drivers side but I'm having a bear of a time getting at the ones by the shock tower.do I need to unbolt the motor mount and jack up the engine on that side?my back was getting a little stiff so I called it a day and will get back at it tomorrow.

Terry
 

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That is how I do that job!
 

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Just be sure to not use gaskets when you put it back together. They always blow out. There were no gaskets originally, and none are needed.
 

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When you are dealing with a big block in a Cougar, there is no EASY way. Just to add to what Royce said, both surfaces must be machined in order to not need gaskets. Good luck.
 

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Actually I have never had any of the surfaces machined. Sometimes they have been pitted from rust. I do clean them thoroughly with a wire wheel if the parts were not sandblasted or vatted first. They can be pretty badly pitted and still seal off perfectly. A light smear of the cheapest RTV you can find works fine, although I have also used Permatex #1 or #2 and silicone bathtub caulk with equally good results.
 

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Discussion Starter #7 (Edited)
I used ultra copper on the leak on #3 last year and it held up until I fired it up this year and it started to leak again that's why I'm pulling both off to get them trued up.Can I run a belt sander over the ports to true them up or should I leave that to the machine shop?
 

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You need to be sure the manifolds sit flush on the heads. Use whatever means are necessary to achieve that goal.
 
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