I wouldn't use 2 cycle oil in an emissions equipped truck. Look into howes diesel defender or Stanadyne lubricity formula, hotshots secret edt, Opti lube, Schafers's soy shield.
I agree, it's a very impressive platform I have a family member that has 03 blazer with 260,000 miles on it that get used as a mail vehicle every day and it just keeps going and going and he's not easy on it.
Having many high mileage trail blazers in the family and my daily currently is a 2007 hummer h3. I have not seen or had any problems with the atlas family of engines the 3.7 in the hummer has 207xxx miles on it and not one engine related issue.
I should have taken pictures but 2007 hummer h3 with the atlas 3.7l inline 5 205,xxx miles.
Out at 2500 miles: Royal purple Hmx 5w30 with one quart of HPL Engine Cleaner 30 Filter was a wix xp.
In: Hpl Premium plus pcmo 5w30 with 1 quart of EC 30 filter Fram endurance.
Will do a c&p of the...