I just installed a Bully Dog 4" a few days ago on a 2002 ETH quad cab. If you are like most and have to cut the OEM system off due to overtightening of the clamps... You can remove the whole thing with only one stratigically placed Sawzall cut. Make the cut about 3 inches after the downpipe hanger rod (the rod welded to the downpipe which inserts into a mount on the transmission). After making this cut you can feed the downpipe up into the engine compartment enough for the cut end to clear the frame member and drop down. You will need a helper to remove the section from resonator to tailpipe. To remove this large section I fed the tailpipe up over the axle toward the front of the truck while a helper guided it all out from under the passengers side of the truck. It also looked like it could be pulled out the back if you remove the spare tire. Of coarse if you don't want to salvage any of the OEM system and have no helper, then cut the exhaust into smaller managable sections. I just wanted to try and salvage as much as possible so I could place it in my '95 truck. I'll probably only be able to use the down pipe and resonator. I'm hoping the emission nazies will think the resonator is a cat. Actually if I'm only able to replace the cat with the resonator and it fools the emissions people I'll be a very happy camper!!
Like mentioned by Big White Beast try placing the muffler forward the OEM muffler location. My Bully Dog system came with 2 sections of straight pipe (a short piece and a long one) I believe I place the long pipe after the down pipe and then the muffler, this placed the muffler about where the resonator used to be. The rear joint of the muffler is now being held by the hanger which originally held the front of the OEM muffler. I was worried about the Bully Dog muffler only being supported by a hanger on one end, but it appears to be solid enough that I decided to leave it there and not move it further back to where the OEM muffler was so it could be supported on both ends. Since I have no welder I was not able to be creative like Big White Beast and offset everything so band clamps could be used on all joints and re-fab a new hangers. For what it's worth I feel the Bully Dog hangers are also lame, the OEM hangers I feel are much better. I'm going to take the old OEM exhaust into a shop and see if they can weld the OEM hanger rods onto the Bully Dog pipe and do away with some of the cheesy Bully Dog hangers which clamp to the 4" pipe. The OEM system had 2 hangers welded to the tailpipe section. Bully Dog only supplies 1 hanger which clamps to the pipe and the fit leaves a lot to be desired... ... one end of the rod hits the spare tire and the other side hits the rear leaf spring when going over pot-holes, speed bumps, railroad crossings, etc. Thus another reason to have the OEM hanger rods WELDED to the Bully Dog tailpipe section.