critical wiring itself is all the same and will plug in and work. some things will vary. d-body probably has an egr position sensor unused on the f-body engine. 1997 engine has a crank sensor that is unused on earlier models. the 1997 coil and opti harnesses are different from the 1994, but you could easily just move parts from the donor engine. the location of the ECM as well as where the connector that goes through the firewall is likely different. knock sensor count and location could be different.

best approach is just lay the harness you like over the engine you like and deal with it. if something doesn't reach, strip back insulation and retape it so it reaches. if connector doesn't match steal one from donor harness.

this will be helpful

http://shbox.com/1/4th_gen_tech2.html#1995_pcm_wiring