The HO came out in 04.5 in the third gens, they were 325/600.

Look for the build date of the truck to be after 1 Jan 04. There are other factors in this, but this is the main one.

 

I just traded my 02 Silverado LT for a 3500 Laramie. I loved my duramax for 180000 miles but I bought a trailer that required a dually. I am amazed with the power but the economy isn't as good as the chev. I think I can work on that. Nothing's free especially power. If you plan on pulling heavy you will appreciate the Cummins.

 

Thanks guys, if I went with a auto trans how much is does the average build cost to support 400-500hp

 

Man, I would not skimp on the tranny. If you're going to build it, do it right. Remember, you get what you pay for.

Where do you live, roughly? Maybe you live by a big builder.

 

Landing, Michigan closest big city

 

How much h/p over stock with the g56 manual hold reliably? & what's the average price for a southbend clutch?

 

Man, I'm sorry...

For an auto, the best builder is probable going to be Goerend or NADP. I am an ATS fan, but I have been using them for a while and have had no issues.

A G56 does pretty good. Paired with a SBC, you have a proven combo. Top end, you're looking at 1200 for a DD...? I have not looked at them for a while. Peter at SB is the best for clutches and customer service.

 

Its all good you've been real helpful. Listed my truck for sale today and began lookin cor a cummins. I got another question, ha. From looking around on here I've found that the 03-04.5 have 3.5" exhaust and the newer ones are 4" besides muffler. So for the 04.5-07's all I would need to do exhaust wise would be upgrading the muffler?? Because on my duramax 4" is plenty of airflow. Thanks again ^^^^^

 

Yes. The 03 and early 04 have a 3.5, but no cat. The 04.5 and up have a 4" with a muff and cat.

I'd look at at least a 4" turbo back with a big flow through muffler. I have a silverline and like it.

 

Almost all of them 03-07's, have heater/ac door problems sooner or later. Cheap plastic stops and actuator mechanisms that strip or break. There are a few fixes, both detailed and fairly simply..... Google "heater treater" for the simple, I might use their hardware, but I would remove my dash, rather than chopping into it.

There have also been electric window control problems, my driver's controls always work, but the rest of them may or may not.

Cruise control issues, surging while empty, mine works well towing.

Cab clearence lights leaking, if equipped, need newer style gaskets.

Those are a couple of the most common issues, nothing that cannot be overcome, but frustrating.

The first HO's(3rd gen) were actually the 305/555 offered in 03/04. They have an HE341 turbo vs HE351 that the 04.5+ years have. As you already know, they also have a 3 1/2" downpipe, no cat.

The 03/04's have two injection events vs three in the 04.5+ years, which generally give them(03/04's) better mileage. 03/04 have 8 hole tip injectors, 04.5+ trucks have 5 hole tips.

As you have found out, lot's of them with alot of miles on the clock. If their fuel filtration has been upgraded to a 2 micron setup, that is good, otherwise after about 100k you will possibly be looking at new injectors. There are also many that have been modded with fuel boxes and programmers, and had the bejesus run out of them, but that's true for all the brands, look for telltale signs.

 

I'm new here as well. Greetings, looking forward to reading all ya'll's posts!

 

Well I took an 06 megacab 3500 4X4 s/b single wheel home yesterday for a 2 day test drive. I love the power difference and all the space but think ill stick with a quad cab, seems to be a liitle too long. The one and only thing I did not like is the seats. They were way too firm and uncomfortable. I'm wondering if the leather interiors are more plush feeling, anybody know? Overall very impressed!

 

My leathers are softer, but it's pleather... My wife has the new seats, they are pretty firm.

Dude, if you ever carry anyone at all in the back, get a mega. That quad cab is too small for back seat riders.

 

Ha, yea the quad cabs are more like my Ext cab with crew cab doors. Ill always be driving so my buddys can deal with that

 

I am not a "mega" fan either, the small amount of time anyone is actually in my back seats, they are just fine.

Not sure it's even relevent, mid year 06, the electrical on the trucks were changed to the canbus system, pro's and con's on both prefrences.