Being a new owner, I am not sure how to tell if my truck is an '04 or '04.5. I ask this 'cause I have seen aftermarket products specify the two. Also how can I check if I have the H.O. engine or not?

 

check on the driver side valve cover. it will say advertised HP. if its an 04 HO it will be 305HP if its 04.5 it will be 325HP

 

in '04 there is nothing but the 305 h.o. no more s.o.'s the '04.5's are 325

 

just look at the sticker on the drivers door. if manufactured 1-04 or later it's 04.5

 

You could also check if it has a CAT.
No CAT on 04
04.5 and 05 have a CAT

Here's something that may help

2003 S.O. Federal Emissions: 250HP/460lb.ft. Available with NV4500 or 47RE
2003 S.O. Calif. Emissions: 235HP/460lb.ft. Available with NV4500 or 47RE
2003 H.O. Federal Emissions: 305HP/555lb.ft. Only available with NV5600

2003.5 The 47RE was replaced by the 48RE automatic transmission

2004 S.O. Calif. Emissions: 235HP/460lb.ft. Available with NV4500 or 48RE
2004 H.O. Federal Emissions: 305HP/555lb.ft. Available with either NV5600 or 48RE

2004.5 (50 state legal) 325HP/600lb.ft. Available with either the 48RE or NV5600

2005 (50 state legal) 325HP/610lb.ft. Available with either the 48RE or NV5600

2005.5 The NV5600 replaced with the G56 6spd manual gearbox.

 

HorseHauler------Thanx for the info. Checked it out the other day, sticker says it's the 325. I'm pretty sure it has the 48RE tranny.

Again, thanx for the tip.

 

I'm planning on getting an 03 HO. How can I tell if its the 48re or NV5600? Will the door sticker say 03.5?

 

It is auto. Does that switch my question to "do I have the 48re or 47re?"

 

If it a 04 HO you have a 48RE auto.

 

03???

 

If its a HO it was the 48RE auto