whats the difference between these engines are the blocks and heads the same

 

think the inlet manifold is different, the phase 1 has indicidual coils. Also I think the heads have different bolt patterns in some areas as well.

 

Blocks the same, heads different and not interchangeable between phases

 

so phase 1 heads fit on phase 2 blocks

 

yes, blocks are the same (some have a different crank fitment however the heads are interchangeable across the blocks)

 

The heads are interchangeable on the blocks however the manifolds from the early cars will not fit the later phase two heads without some work. You will also find difference in the looms and fittings from phase 1 to 2 etc. There will also be diference on the internals depending on year and model.

The best way would be to stick with what phase you have now as it will make a swap more straight forward.