My wife and I had an 06 I think Trailblazer. Ran amazing got great fuel milage we just had continuous issues with 4 or 5 different sensors always going bad. The aftermarket support isn't all that great. Parts can be had but at a premium from the looks of things.We had a trailblazer for about 6 years that had one, no issues whatsoever with it. Not sure what he aftermarket support is like for them though.
Chevy 4.2 litre all aluminum inline 6 can be found I Chevy Trailblazer, GMC Envoy, Saab 95x I think and maybe one or two others I don't know about. I think they depending on the year they're rated from like 270-290 hp. Bad things right off the bat it's tall, long and the oil pan is cast and has a pass through for an axle shaft on all models 4x4 or not.1st I've heard of it