Yes. Removing the fan and all of the associated piping. Then you need to source early plates that go on both sides of the engine fan and pipe the tubes directly to the heat exchangers. Basically you eliminate the fan in the upper left and use the engine fan to push air forward to the cabin.
This is also often done in conjunction with adding early heat exchangers or SSIs for better exhaust flow. Photo below stolen from google image search.
http://www.google.com/imgres?imgurl=http://forums.pelicanparts.com/uploads5/enginebay31115691174.jpg&imgrefurl=http://forums.pelicanparts.com/porsche-911-technical-forum/220695-why-you-should-backdate-your-heat-3-2-a.html&h=480&w=640&tbnid=duKT73r0ZmH4mM:&q=backdate+heat+911&docid=ZHZAUffCtNZmMM&ei=c4crVs-aLsr2mAHEiqWYBw&tbm=isch&ved=0CB8QMygDMANqFQoTCI-g2Jyb28gCFUo7JgodREUJcw