yes
does a 1990 honda prelude 2.0 s.i have a pilot bearing
http://www.modifiedlife.com/1990-honda-prelude-car-radio-stereo-wiring-diagram/
No, the third and fourth generation are a different Chassis.
no
6.5"
NO, they have two completely different motors.
the fuel rail
It's hard to say, as the question didn't specify what kind of solenoid are you attempting to fit, and the 1990 Prelude had a mid-cycle refresh which included an improved motor.
1990-91 Honda Prelude Si, not the 2.0si
about 135 140bhp
6000000