-6 degrees is fine as a starting point but what gets results on one engine won't give the same results on every other engine. Hence i said - for the best results - it will need an hour or so on the dyno, probably less actually as it's only 1 cam to tune up. I had Chris Todd swing a pair of Piper cams in my 1.8 Zetec and gained around 8hp and 7ft/lbs of torque in an hour's dyno time so don't doubt there are decent gains to be had. I definitely wouldn't call it a bolt-on mod though.