Long tube headers are not available for 4x4 GMT 400 trucks, BC the transfer case is in the way of the passengers side header. So your only choices are, make a set of long tube headers, ( or have it done for you) and then I'm not sure there is enough clearance to run that on the passengers side, no mater what you do, or run a set of shorty headers. Shorty's are grate for low end torque. That's where they perform. Once the RPMs build, long tube headers are much better. I never heard of shorty exhaust. Are you talking about turn downs? As for the 9ld school glass packs, I have a set on my 2wd with a set of Summit shorty's, and I love it. I get a lot of compliments on how my truck sounds. My GP mufflers are 24 inch long thrush brand mufflers. I also gutted my cat's, and I have true dual exhaust out the back, with a set of SST tips that I built.