87 octane
Should be Dexron III. However, look on the dipstick, it says on it, at least it does on my 2004 Trailblazer.
GM tends to recommend 5W-30 oil.
The newest and most up to date version of Dextron fluid. It is all backwards compatible however contains the latest and greatest antiwear agents etc. Not sure if it is 4, 5, or 6 by now? LOL! www.trailvoy.com All the answers for your Trailblazer from true enthusiasts!
I would recommend the OEM spark plugs, AC/Delco. Excellent plugs.
R134a
R134a
Grade 93+, your manual should have this info.
Regular
if it has been rebuilt regular unleaded,but if it has alot of miles mid grade or high grade
um proboaly 10W30
Dextron III
Ngk br8es