Shorty or Longtube? I wish we had LT headers...they are all the same...Primary wise they are mostly (as in around 1/2" difference) the same too...The black painted Pacesetter's are junk unless you never plan popping your hood to show anyone anything...EVER...they rust in about a months time and look like your stock manifolds...I got the coated ones...have had them over a year...and have touched them with grease, spilled tranny fluid, coolant, and even motor oil on them and they are fine

IMO no headers are EASY to install, just some easier than others...I love my Pacesetter's...and no...the Pacesetter's come with a 3" Catted or Catless Downpipe and the ZZP one would end up having to be sold when you install these. If you never plan on going past a 3.4" the PLOG and Catted 3" ZZP Bolt-In Downpipe are fine. Headers are great but will only help so much on a 3.4" setup...Headers and Rockers though...or a Cam and Intercooler...then your talking