Not 911 but when I stuck a 2.8 into my 356 I pulled the torsion bars and went over to Koni coilovers with 110lb Eibach springs. I don't race but do trackdays and last time out I lowered the springs to give me a bit more travel and it worked well. My rear suspension is s/w/b early 911 and I extended the banana arms to pickup the Konis as per the pic. OPverall much better than the old torsion bars.
