I can tell you for certain that the Yugo injector placement differs from the X1/9 placement. I did have to do a little massaging with the die-grinder to make it so the injector wasn't squirting right into a wall. I took the time to clean up some casting flash while I was in there, too. I was holding out for a Yugo intake manifold, but I still haven't seen one pop up, so that ship has all but sailed. I'm sure the port shape is far from ideal, but I seen much more heinous port work make good power on FWD VW stuff.