This may be a dumb question but how can you tell if you have the SO or HO engine. i have an early 03 6spd. i looked on the valve cover but i didnt see anything, its the 305hp engine. Thanks for your help. Daniel

 

If its the 305 hp like you say, then it's an HO. Also I think the SO was only available with the 5 spd.

 

The HO 355 HP came out in mid year 2004.5 . The 305 HP I thank is the SO. But I am not a guru as some on here..maybe somebody might chime in that knows for shore.

 

No.

Previous to 2004.5 Dodge/Cummins had two different output motors; HO and SO motors. After 2004.5 there was only the "standard output" motor of 325 HP / 600 ft. lb.

Pre 2004.5 the HO motor was rated 305 HP. You have the HO motor (305 HP / 555 ft. lb). The pre 2004.5 SO motor was only attached to the older automatics (47RE). You have a good motor!

 

03 305 h.p. was the H.O.

 

Some SO's came with the 48re but you have a HO

 

The SO was only rated around 275 hp if i remeber correctly. Also, your vin number will tell. The 8th digit is a "C" for HO and a "6" for SO.

Jason

 

alrite thanks for your help. Also how can you tell and what is the differance between Eth and non ETH... and what does it stand for

 

03 SOs were rated at 250hp/460tq. The California SOs were 235hp/460tq.
03 SOs started out with only the 47re available but once those trannies were exhausted then they started making them with 48re's. There were also some 04 SOs made with the 48re. If your engine has the 305 on the tag then it is an HO. If it is a 6 speed it is an HO. If it has a 5 speed then it is an SO.
Starting in 04.5 they were all HOs. Even though there is no longer an SO offered they are all still considered HOs...
I don't know about the ETH question.....

 

Looks like ETH is the code for an HO and ETC is the code for an SO. That's what I gather from doing a search here.....

 

How can you tall if a SO motor has the 48re tranny? Sorry to hijack your thread!

 

There's a tag in the glove box that will give your tranny code. Find it and then just do a search here for the code. I'm sure someone else here has asked that before..

 

Cool thanks for the info!