Hey guys. Just bought my first duramax yesterday. A 2006 2500 LBZ with only 40000 miles. Ive had a few generations of the cummins diesel but I wanted to try one of these. The owner before me installed a 5 inch MBRP exhaust but since the downpipe looks factory I am assuming that it is a cat back system. Thats the only modification he did besides the 6 inch lift kit. I have two questions. The first is what would be the best intake/programmer/exhaust combo for my truck and the second is that it seems to shift kind of hard. harder than my cummins did. Is this normal for a Allison transmission or should I be concerned? Thanks in advance all you vets out there.