Recently build a 4.6 out of a 4.0. Used studs which was a lot easier than bolts and safer on the block.
Used standard head gaskets (Elring?) but sealant only around the water passages (but I cannot see why not to give the entire gasket a squirt as well) - evidence on the 4.0 block showed the gaskets had held up well but there were coolant leaks around the coolant passages so hence the sealant there - same with the tin valley gasket when it is time to put the inlet manifold on.
Engine has not covered a lot of kms but seems to be holding up well.
Garry
