My father had a mid-90's S-10 Blazer with a 4.3. I was unimpressed with that engine for many of the reasons that people already listed.
So, when my brother saw a cheap, brand-new 2006 Silverado with that engine for sale I was reluctant. Anyway, I went and test drove it. The engine performance wasn't spectacular but it was way better than I remembered my father's being.
The 2006 4.3 has port injection, Vortec heads, roller cam, and dual cats. It makes good power if you spin it up. I've gotten over 20 mpg on the highway hauling a 1/2 ton of stuff. It has been reliable.
My main gripe is low-end torque. I'm used to the straight sixes in our old trucks. The 4.3 gets the job done, but I'll never forgive GM for not putting in the redesigned six-in-a-row into their new pick-ups. I mean - what were they thinking?!?!
