Best mounting of HP manifolds

[AMXguy]

Since these HP manifolds have a reputation for cracking should you use some hard washers or anything under the nuts where possible? and the book calls fot 30 lbs torque, is there any logic in less so they can move or will it just cause problems?

[Blue Stone]

 Clean up the mating surface (manifolds and heads) check them with a straight edge if good new gaskets and torque em to factory specs, that what I plan to do with the stock 440 hp manifolds that I bought,,,,,,,, have not yet searched out washer and nuts but originally I think they had spark plug shields that mounted on the manifold studs, I bought those too but not sure if they were on a 70 440 Six Pack plan to use them any way....

[AMXguy]

Yes I think the heat shields were on all of the engines, those whould act a little like a washer but pretty weak. I've never used the gaskets before just some copper silicone, I don't think you want them in there unless your manifolds are junk. I'm not sure if the factory used gaskets on HP manifolds or not?

[femtnmax]

The cracked 440 exhaust manifolds I've looked at cracked in the tubing junctions, not at the bolt hole locations.  Can't think that washers would be a bad idea though.
With a new rebuilt engine, after the engine has been run a couple times I always retorque or tighten every single fastener accessible on the outside of the engine, from valve covers, intake/exhaust manifols, water pump, cyl heads, etc to oil pan.  Then check again after 1000 miles.
I also retorque the cylinder heads within 100 miles or less of initial breakin, then again at about 1000 miles. 
Even the Felpro permatorque type head gaskets will show uneven compression, and thats after torqueing them down in 10 ftlb increments, followed by one at a time loosen and torque to final spec with a single clean sweeping motion.

[Chryco Psycho]

I have aways used no gasket other then a thin film of Ultra Cpper silicone to seal them , as was said above any cracks I have seen have been away from the bolt holes in the middle of the manifold , have a stuck heat riser may be the cause as it over heats the manifold