Questions about a DOD 5.3L swap

[Mtnsackett]

I am thinking about swapping a 5.3L with Displacement on demand in to my 85 GMC short box. I'm wondering if anyone has done this before and if so can you easily add more power with out sacrificing fuel economy? I'm not looking to race the truck but to have a nice truck that I can use for cruising and still have some power to lay a little rubber once in a while.

 

[Edhard_Stark]

From what I've seen people end up losing power and having less than desirable performance when they keep DOD. The lifters usually end up needing to be replaced, at least in the G8's. G8 guys make huge gains when they swap it out, and supposedly only lose about 2mpg without it.

 

[Mtnsackett]

I assume that you are referring to the Pontiac G8

 

[AJII]

All DOD lifters suck. Just swap in a regular cam and ls7 lifters and call it a day. The difference in mpg is negligible at best. And these trucks aren't exactly aerodynamic so the MPG isn't what a new truck would get with DOD anyway.

Throw the 5.3 in and enjoy the power and reliability.

 

[HotRodPC]

As a matter of fact, we have a member here with a Burb and a 5.3. He converted the cam, lifters and had a PROM chip tune and tuned out the DOD for being problematic. The system seems to work well, but as stated, the hardware doesn't last and gives problems. Chances are the funds you'd save in fuel, you'll eventually end up putting right back into it replacing hardware in the engine, so you may as well just do you a good 5.3 LS Swap without the DOD and have the dependability. JMO

 

[scottybaccus]

Swap out the parts.
If mpg is on your mind, use a higher gear.
I'm getting 20+ mpg with 3.08 gears behind my 6.0/4L80e.

 

[HotRodPC]

That is a Yes/No suggestion. All depends on your usage of the vehicle and driving habits. Taller gear can hurt more than it helps along with turning it into a slug and putting more of strain on the powertrain.