304 BIG BLOCK GM V6 was most dependable GM engine. When GMC stopped making their own truck engines and switched to Chevy we started the slide to mediocrity.
I owned a Silverado Trailboss 2.7T. Loved it. Many fellow neighbors and friends have GMC and Chevy 2.7 T versions of Colorado and Canyon and love them. I think the lower HP 2.7T in either one would be ideal for efficiency durability and life.