97 is the change over year.
the flex plate is weighted and the torque converter is neutral at that point vs weighted converter on the 95.

not positive on the harmonic.

all electrical connectors changed about the same time, so as stated above you should have reused the whole harness and sensors from the 98 if you are running it with the 98 computer.

the only other thing I can think of is timing. there is an arrow in the distributer telling where number 1 must point or the computer cannot control the timing properly.