I have never heard a gibson system on a ranger, but they do sound pretty good. Alot of guys run a flowmaster 40 series dumped right in front of the rear axle. I am running a flowtech red hot glasspack with a 4" stainless steel tip. It sounds pretty good. Not too loud, but noticable if you get the revs up there. My buddy keeter has his ranger straight piped. Sounds pretty aggressive, plus having the 5spd manual helps too. Both our trucks have the 4.0L SOHC V6.
If your looking for a deep throated sound, I would recomend a dynomax ultraflo welded muffler. They have a straight through design that allows for max flow, and the CRF (continuous roving fiberglass) delivers and aggressive, powerful, deep, performance sound. Plus the flow comparison is pretty outstanding.
Dynomax UltraFlo... 1133cfm
Flowmaster 50 series... 435cfm
Gibson... 311cfm (ouch)
If you need part #, and pricing let me know. I sell these muffler alot at my work. I work for a auto parts store.
1999 Ford Ranger XLT ext. cab 4x4. Level 8 Tracker wheels. Nexen Roadian MT LT235/75R15. K&N air filter. Sony MEX-BT3000P Stereo. Rockford Fosgate Power T1682 6x8" speakers.
2002 Ford Ranger EDGE 2wd. Thrush welded muffler. Spectre air filter. STK Pro Rack. Curt Hitch.