I was just told that I should be able to use any muffler that is for a gas engine on my TD.....is this true??????

Provided it flows enough, yep, it won't care what kinds of exhaust gasses are going through it. Naturally you wouldn't want a Honda Civic muffler on it:) . You should try to find a minimum 3" inlet and outlet if you still have your stock exhaust on there.

But really, if you have a 6.5 thats turboed, the turbo kills enough noise that most people don't even run a muffler at all. Straight pipe on a turbo diesel is still quieter than a gasser with glasspacks.

This is, of course, provided you're not in a place where they'll fine you for no muffler based on a visual inspection(in other words, they don't care how quiet it is, if you don't have a muffler on there you're in trouble).....and if that's the case, well, the insides have been known to "fall out" of mufflers, leaving them looking stock but flowing like a straight pipe.;)

i dont use any muffler at all. let it breathe and exhaust. get as much air in and out as possible. the turbo needs air and if you pop the muffler and go with at least a 3" exhaust you will really notice the change on the 6.5td. there are many places to find 3" to 4" systems on the web i would look into it and uncork that thing.BOWTIE 65 95 chevy k-3500 4x4 ext. cab 3" st. thru exhaust banks chip no snorkle heath turbo master #9 resistor and a boat load of power with no toys to haul.:D