My son bought a very-low-mileage (86k) '89 Sentra but it was running kind of rough. Mechanic said the throttle body was the problem. Says cannot be rebuilt b/c something on it broke when they tried to take it off. LS/S (long story short), they're saying it needs a new throttle body. Problem is, part is no longer made and can't find one anywhere.
SO-- my question is, is there an available throttle body which can be substituted, with little or no 'major' modification, on the E16i engine?

You sure it’s an e16i because the ga16i is the motor for the 89 sentra b12 I had one, the throttle body injection usually goes bad, solution would be swap a ga16de intake manifold and swap the harness with injectors and manifold and computer and call it a day and it would be so much better