Bully Dog or Pittsburg Power on Detroit Series 60?

If it's an older detroit I thought they were real easy to turn up without a ecm program.

 

I've run the Powerbox on a ddec4 and a ddec5. They do what they say but I never ran it on more than #3 setting. You get an instant power increase which is kind of nice if you like to lug your motor down low. It really helps the ddec5 thats geared for low rpm. I didn't get much mileage increase on the ddec5 rated at 515 but it made a big difference on my 430 horse ddec4. of course you also get increased engine heat, not a problem with a Classic but can be a problem with a Columbia. The Powerbox can't start the injection cycle early so it adds fuel to the normal cycle which actually slightly ####### the timing and causing increased engine heat. The bully dog modifies the injection timing which will make you engine run cooler. I don't have any experience with bully dog. If your main goal is fuel mileage I'd think about the bully dog for the ddec5. I was disappointed in the powerbox on my ddec5 but very impressed on my ddec4 as far as mileage goes. Power wise it did as advertised.