Anyone know how difficult the nuts and bolts are to remove on the exhaust manifold. I attempted to replace the bolts holding the heatshield on and two of them sheared.

 

Spray penetrating oil on them for a few days before you attempt to loosen them. They WILL be rusted, heat warped, etc.
Make sure you have the correct size socket in good condition. It would be wise to replace them while they are out.

 

The nuts on the manifold itself (not the heat-shield) are one-time-use, so they should definitely be replaced. I got them from my dealership, and they are not expensive. Do NOT try to use nylock nuts or regular nuts; you will not be happy with the result.

 

Thanks for the info guys. I sprayed them with pb for a couple of days and loosened them today with ease. Actually, upon loosening them I found out that they were already loose so I tightened them all down temporarily. After I get new hardware I'll change the gaskets. Sure did quiet my truck down a lot.

 

Put copper anti-seize on the new bolts/studs. It makes life so much easier!