If you want a little extra "oomph":
Do a compression test to make sure the seal is tight in the cylinder. Do a complete ignition tune up. And look into a "wet" N2O (nitrous) set-up.

You may have to buy a "universal" kit that may need to be slightly modified, but an I6 that's up to use of forced induction, should be able to handle a 75hp boost of N2O.

Nitrous isn't any more damaging than forced induction. The main thing to worry about is detonation (aka pre-ignition), which both poorly tuned forced induction and nitrous can cause. A wet setup injects fuel as well as nitrous. A "dry" setup only injects nitrous. By injecting additional fuel, you cause a "rich" condition. Which prevents detonation. It's just easier to tune...and cheaper

Another thing to consider is that in I6 is more balanced than a V8, plus lighter. By adding a compressor, turbo or supercharger, your adding additional weight to the front. With a nitrous kit, most will be in the trunk.