If you go to the Inliners site, there is tons of guy using the GM 4200 I6 form Trailblazers and Envoys. Some are even throwing turbos at them. Seems like a real solind setup.
I'm surprised by this, but I still wouldn't recommend it. These engines were notorious for poor fuel economy and low power in the Trailblazers (The I5 in Canyons and Colorados is just as bad). You're better off with an LS as they're more readily available and swap parts (including aftermarket harnesses and performance parts) are much more common for the LS than the inline engines.
