2005 Chevy Trailblazer Ls interchanges with what?

buick rainier is a sistership truck

Depends on what you're wanting to swap. Engine wise 4.2 , I'd stick with 03-05. 06-09 has the temp sensor relocated on other side of engine, has MAF's too unlike prior years that rely on MAP's to do the job. Suspension and brakes are identical 02-09. Most mechanical parts are the same for all years of the LS Short Wheel Base ie PS pump, water pump, fan clutch, alternators, radiators, ac pumps, all pulley's and so on. Stay away from 02, it's kind of a unicorn. First year production, has a few differences not found on any other year.