I'm just going to put new studs into the engine block. Do I need to lube them? and if so what with?

Kelvin

Studs are meant to stay in once fitted, definitely don't lube them. Use a stud locking compound like Loctite 271, although effectiveness at exhaust temps isn't guaranteed. Ideally studs are meant to be wound in hand tight, not rammed in. This doesn't always work in practice, but if you use a pair of nuts to wind the stud in be careful not to over tighten it in an ally head.