Nice sand blasting job.. make sure you get all the grit out before you put it back on... That sand or glass can destroy a perfectly good engine.
Have you looked into boreing out the TB and using the larger 3.5 litre air flow meter (from 535 or 635) along with bigger injectors? I wish i had a link for you but someone here might.
Oh and please update on the pro's and con's for the new injectors
E30 Stuff For Sale: Clutch Fan and Shroud, 4 Pack Ignition Coils, ATE 750il MC (New), Offset Trailing Arm Bushings, m42 Valve Cover (Clean), M10 Engine Mounts (New), M42 Injectors,