Can I build one engine from a 120 and 140 Mercruisers?

[kingoftex]

I have a late 80's or early 90's 120 hp Mercruiser with a galded cylinder, but a good head, carb, manifold and starter. I have a '73 140 hp Mercruiser that probably still has the original "Lead gas only" head. It also has carb problems. Can I put the head, manifold carb and starter from the 120 onto the 140?

I'm sure I'm missing some important info, but any help will be greatly appreciated.