On POST-88 models the ignition is timed to a crankshaft position sensor, mounted on the bellhousing. Rotating the distributor won't change ignition timing.

One other performance mod is to block the hot air feed from the exhaust manifold 'stove'. I opened up the air filter box and removed the flapper door and the failure-prone thermostat. I also removed the silencer 'horn' from the ducting which feeds air into the filter box from the grille area. Make sure your air filter is clean.