Dearth, the main problem w/ all these ol 6's on the highway is the rearend gearing - you've prolly got a 3.90, which will put any engine up at it's max RPM above 60mph, so yes ... they all sound like that stock
"When we tug a single thing in nature, we find it attached to the rest of the world" ~ John Muir "When we tug a single thing on an old truck, we find it falls off" ~ me Some TF series details & TF heater pics