type Iv in a type III square?
 

how hard and what mods would i have to do to make a type IV engine fit into a squareback...that would be sick GL wagon...I could actually hold my string bass in it

From what I know, there should be no physical fittment problems, maybe flywheel, but that's it. It already has the "pancake" cooling tin, so it will fit.

It has been done before, so I'm sure you can too.