Does anyone know of defining marks or a code that would tell you if you have a high output motor.
The truck is '04 quad cab 2500 4x4 and on tailgate is heavy duty

Thanks in advance for your help

 

Lookon the drivers side of the engine. There is an I.D. plate that will say ISB305 or ISB325.

 

with the 04's you have two engine offerings. the HO 305 or the SO 285. however for 04.5 the SO's went away and now everyone gets the HO 325hp engine.

Blue is right, look at the white sticker and on the back end it will show you the advertized HP. if you have a 305 you have a HO 04. if you have 325hp it is an 04.5

 

Thanks guys