84-86 engine will work but:
use 84 engine harness. C500 is different.
use 84 dist and coil or splice in new ICM and coil. Second option maybe easier to find ignition parts.
gm change throttle cable and TBI connection. Use 84 TBI or find correct cable.
5 speed need shifter cables, maybe shifter.
84-86 ECM different # but does matter. Prom have some minor changes but will work.
w/o headaches, 87-88 DIS engine is allot different wiring and can't use 84 engine wiring harness w/o issues because 84 is only made to use "old type" l4.
switch dis motor is easier for 85-86. Later years are made for use w/ different power trains as plug and play items for C500 and C203.
also See my Cave, Duke Quick Ref
------------------Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)The Ogre's Fiero Cave
(It's also at the top and bottom of every forum page...)
[This message has been edited by theogre (edited 04-09-2015).]