390 ex. manifold gaskets how replace?

[greg]

390 cu in 1962 engine:  Is there a way of replacing exhaust manifold gaskets without removing engine or what is best way? I have a shop crane but no hoist access.  Im assuming the manifolds would not need machining or is machining a must since these may be the original gaskets? thanks.

[JIM CLC # 15000]

05-23-05
Greg, your biggest problem will be to remove the manifold bolts with-out snapping one or more off. If you are dead-set on changing the gaskets, be sure to soak the bolts with a good grade of penetrating oil for a few nights Prior to attemping removal. P B Blaster comes to mind.
If it were mine and I were going to that much work, you can bet your a>> I would have the manifolds re-surfaced. And be sure that the surface of the block is super clean prior to re-installing them.(Use New bolts and an anti-sieze compound on the threads. you will not need much,I think most GM parts have it)
Good Luck, Jim

[Bruce Reynolds # 18992]

Gday Greg,

Yes, Exhaust Manifolds on a 390 can be removed without pulling the motor, or the heads, unless you break a bolt, then either the head must be removed, or the engine removed to access the thread for repair.

Sometimes it is easier to remove the motor to effect the repair as removing the head will then entail the cost of new gaskets, and if you are going to pull one, then you will most probably find that the guides or seats are worn, then you have opened up a can of worms.

And, whilst the engine is out, give it a clean-up, a paint, detail the engine bay at the same time, etc, etc.

Just pray that the bolts come undone.

Depending on how bad the leak has been, and for how long, you might get away without having to have the surface ground.

Bruce,
The Tassie Devil(le),
60 CDV