The Raptor Turbo muffler from Kragens is nice sound for the price($24). I run one with headers on my 3.0, the sound is good/throaty when on the throttle, but also mellow when idling/cruising down the trail.

More than tread lightly. Leave it like you were never there, nor anyone else.
'90 X-cab 4.88's 33 BFG AT's, rr ARB, Headers, Ignition upgrade, cold air induction.
'91 X-cab 5.29's 315's BFG MT's, rr ARB, custom bumper and flatbed