I used this kit on a previous project - installed well and sounded good with the included mufflers.
Blazer specific -
http://www.heartthrobexhaust.com/4159M.html
Full page of options -
http://www.heartthrobexhaust.com/manifolddualkits.htm
Install instructions -
http://www.heartthrobexhaust.com/4159M.PDF
You can also email them if you want to hear the sound clip of the blazer setup -
http://www.heartthrobexhaust.com/soundclippage.html