Ok, now I am fabbing a look-alike Cat for my '05 GMC, and I want to use my Pred to change a few things. What wisdom is out there on how far I can raise my RPM limit, My buddy has a LBZ and his redline is way more generous than mine! Should I just leave well enough alone? At the same time, I would like to be able to cruise @ 200 KPH down the autobahn, how high does one set the top speed? Are there any of you who have had some success with this?