Stock Exhaust Manifold Removal - 69 SS 350

[camaronut]

Looking to remove my stock exhaust manifolds in my SS 350.. any pointers before I tackle this?  Looks like the passenger side is a breeze, but the drivers side looks a bit more of a pita.
Appreciate any real world experience on this…. thanks!!

[Sauron327]

Piece of cake and self explanatory. Just unbolt what is required. Only been doing this 45 years. If you own a classic the simple things should be no problem.

[camaronut]

Looks a little dicey on the drivers side, didn’t know if I had to remove the temp sensor or not.  Then I’d have to empty the coolant. Just bs like that..

[David K]

Depending on how long they have been on the engine means everything when it comes to removal. How long?

[camaronut]

Hey Dave!!! Maybe for 15 yrs or so.  It s/b easy- just wanted to know if there were any hiccups that could get in the way.

[David K]

Sorry I didn’t see this reply sooner. Yes there are. The bolts could be seized in the head and could snap off if you hammer them with an impact gun. I typically apply a ton of  PB Blaster a few times and allow it to soak for a day. Always use a 6 point socket. Always. Slowly attempt to free them up. Feel free to PM me.

[camaronut]

I don’t think I’ll need an impact gun on this one… bolts are pretty clean - hell - the car goes nowhere.  But I’m pretty sure they’ll come out easy - at least I hope so.

[David K]

Best to apply some free me up stuff. I actually loosen them up a little-each one-and then spray lube between the manifold and block to allow it to creep up the threads. Then if they’re tight I work them back and forth. But if they’re loose, I just take out the middles first. Use an air ratchet.
Going back in-I clean the threads on a wire wheel and apply anti seize on the threads. Use a torque wrench. Upload a picture or 2.

Looks like the passenger side is a breeze-Famous last words.

[David K]

Well?

[David K]

I guess they’re still in the engine.

[camaronut]

Good ol Covid  - stopped me in my tracks.  I was gonna do the swap this weekend but nope!!!  Maybe next week.

[camaronut]

Performed the swap - no problems  ---  Until I started the car and heard exhaust popping from the passenger side - middle-two exhaust where the manifold meets the head.  Pulled it off again, and I didn't notice (total stupidity on my part) that the exhaust manifold surface where it meets the head was not totally flat - iow, had rust pits and it wouldn't seal up real nice. 

Now what!....LOL!

[David K]

You installed new gaskets?

[camaronut]

Never installed gaskets because GM never used them initially.  I could try that, but I'm just going to repaint / reinstall the one that I took off.  It's in good shape.

[David K]

I installed them all the time because I did not want to do it twice.

[camaronut]

Not gonna argue with you on that!

[David K]

You could find a local machine shop that could true them up, but gaskets are cheaper and last a long time.

[camaronut]

I "trued up" the manifold surfaces with a large aluminum block for flatness and 320 grit sandpaper.  Goth them really nice and flat.  Reinstalled it yesterday (hell - I got this "down-pat") and it worked great - no leaks - perfect.

So - to end this thread on a positive note, the manifolds can be removed easily - the drivers side takes a little finagling - the passenger side is a breeze.