Briggs & Stratton Opposed Twin and V-Twin Engines? (1 Viewer)

What is the difference between the 2 Engines? mine appears to be Cast Iron but is that just the sleeve or the Bore too? It is a 16 Horsepower 42A707 is the model. My dad gave it to me then I paid $50.00 to put in a fresh Battery. It runs no smoke,pops or knocks once in a while it will surge up and down needs an Oil Change and Carburetor cleaning. 656cc? where the V-Twins available in Cast Iron also? The Engine Guard is made of Metal as well not sure what type though.

Opposed, is opposed(or flat/boxer as BMW, Subaru and Porche call it)

V, is V.

Dup