Difference between heads

[hotsauce]

Did a little searching, but didnt come up with the answers i was looking for.

i just came into a 1.7 type 4 engine that im going to be putting into my bus and would like to put the Porsche heads on it if possible.

What is the difference between a stock type 4 head and a 914 head? Bigger valves and higher compression?

Can the different engine size variations be swapped? IE: put 2.0 heads on a 1.7 if i upsize the pistons/cylinders and bore the heads accordingly.

Is there a "slip in" P/L set that would work, so i dont have to completely dis-assemble the engine?