I am thinking on selling my Impala and get a six seat car /SUV from the GM manf.
I am thinking on 2003-05 Trailblazer /
I know that GM makes very good 3.8 and 5.7L engines but I think that the trailb has 4.2 V8....any ideas or comments on what is better 4 a family of 6?

Thx

Or should I look at Buick Rendezvous?
Which is better from those two?
Which engine should I look for?

I own a 2002 TB, I would suggest you look at consumer reports, in general these trucks have been troublesome to at least 2004. The engine has not been the issue though.

If you spot an '05-'07 TB or Envoy with low miles, clean, no wrecks, regularly maintained, you're likely to get good service out of it for quite a while. GM had fixed most if not all of the earlier model year bugs by then. The standard powertrain is an aluminum 4.2 L inline 6 cyl w/ 4 speed/overdrive auto trans. Unless you honestly need 4 wheel drive the 2 wheel rear drive is ample and less-than-half the potential headache. It's a mid-size SUV on a Chevy Silverado/GMC Sierra P/U chassis. Buick Rendezvous is a mid-size crossover with a V-6 (3.6 L, I believe) and front-wheel drive. I think the TBs/Envoys were better overall. It'll soon be moot, as GM will be phasing out those vehicles in favor of its new generation of crossovers, Buick Enclave, GMC Acadia, Saturn something. They're pricey, closer on a par with the Lexus crossover SUVs.

You can make a good deal on a used TB or Envoy right now from an individual or coming off lease at a GM dealer's, if you shop carefully.

Hey BRD.....hate to rain on your parade, but the TB/Envoy is most definitely NOT on a Silverado/PU chassis. I believe it is on GM's GMT360 platform and is exclusive to the midsize SUVs.

I'm happy to take your word on that "360" chassis. I don't see it as a criticism of the vehicle.

nope...not a criticism at all. I drive an 02 TB and am happy with it. The GMT360 is probably closest to the Colorado chassis, but there are significant differences in those two chassis also. The TB chassis was designed to be much more car-like with coil spring suspension in the rear, and a front suspension that is radically different from any other SUV GM produced at the time. Luckily for us owners, it is just "trucky" enough to pull a good load too.
No criticisms, just trying to help with some info.