i run the QA1 on the front,,they bought out carrera... and strange on rear with hyper coil springs....
so far i have not got a clean 60 ft just yet..but i did post a 1.32 60 ft with a wheel stand and peddling car...car is 3100 lbs...if this tells you something about the springs and shocks i run..
whichever you choose to go with be sure you get the bearings and races that go at the bottom and/or top of shock/spring that will make it much easier for you to adjust with spanner wrench.
good luck brian
http://www.carrerashocks.com/qa1_ind...absorbers.html