Engine Spec. Differences

Besides pistons, camshafts, and cylinders what are the differences between the 2.4 S and E engines? I heard the MFI pump units are different (different cam?) as are the injection stacks (taller?). Are there any differences to the block, crank or rods? I looked in all my books but they don't seem to cover the part details.

I've stumbled upon a rusty, frozen 72 S motor that could be for sale and I'm wondering if it's worth saving for parts or as a base for building an RS motor.

Thanks, Chris

the things you have mentioned, including the MFI pump are the only differences between the 2.4 E and S. There are guys here who know alot more about this than me though.