Propane should get the manifold hot enough to get studs out of it. But then again as the saying goes, one can never have too many tools.
But i have no experience with oxy/map-propane torches, having invested in oxy/acetylene quite a while ago. Back when I was sweating a lot of copper pipe, we used air/acetylene, but have recently done that up to 1" size with a plain ol propane torch.
