The HardRock was a chill trail bike. not a race bike. So Carbon anything was not stock. the HR was the entry level bike, aimed toward casual riders..bike paths and fire roads. The Rockhopper was the next level up for more performance. then the Stumpjumper was the top tier. the Stumpjumper had race level builds. it was light, low and fast. I am not sure of your question. but there are couple of upgrades from the stock HR. nice bars. I had a 91 Stumpjumper base model. very similar to yours but drivetrain was mid level. definitely steel bars. I rode it to death in NorCal. my first MTB.

Your bike looks great. Enjoy the dirt!