I had a glasspack on for a while, till it met a rock and decided to marry it. At first I though it sounded nice but after awhile I began thinking it made it sound like a rice rocket. I now have a cherrybomb extreme and I love how it makes my blazer sound. As for pricing check local part stores, for me AdvanceAuto had them for around $25 when I bought mine. If you intend on wheeling with you truck I will say get it welded and not clamped, lost mine so many times lol.

 

I welded a glasspack on mine, sounds great. IMO

 

I installed thrush glaspack on my 4.3 didnt run duals like i should have but all i did was cut the oe muffler off before the flange that the muffler bolts on to and i just put a close section of pipe 2.5" welded pipe in to old exahust then to glaspack then put a 45 degree turn down right after with no pipe between but then cut the cut down off and i like it better w/o turndown. It sounds deep and throaty imo in was simple also you will need a hanger for the glas pack it was only 29.99 at autozone 29" over all length and 2.5" id inlet and outlet hope that helps!

 

They do sound deeper with a wider tip, when I put a 3" tip on mine it made it much deeper sounding.