What does an RS2's engine look like?

[DeWitt Harrison]

I think a q-lister recently mentioned in passing that he
had converted a 3B engine to RS2 specifications. It
dawned on me that I don't really know what that means.
Does the head/manifold configuration of an RS2's
motor resemble a 3B? What would be a good resource
to learn the details?

Thanks,

DeWitt Harrison
'88 5kcstq