new to me 05 3500 drw quad cab. thought it was a 325/600 but window sticker(guy keep everthing.man after my own heart) states it is 325/610. built 06-05 which I thought was 06. If it is 325/610 any xmission changes.
Clark

 

i got a '05 HD and no there is no emission or smog crap on the truck. people say the 5.9 is the way to go and i have been very happy with mine. did have some injector issues but covered under warranty. i was not working the motor hard enough.

david
socal

 

Look on the drivers side of valve cover. There is a sticker that has engine specs.

 

eng. sticker just says 325 hp. model isb325 cpl 8421
Clark

 

The 05's are 610's and yes it has a cat.