the underhood will work for you
you can use the dash harness, but needs some patch work for the tail lights and fuel gauge hook up,seat belt buzzer,,dash back to bumper is slightly differnt on a RC over a truck.
but I have used them before no problems when patched up correctly.
here is the mess I fixed, removed all wires not needed under hood,tucked out of sight behind fender brace and inner fender.
I run a points dist with a points conversion,BR by-passed for full 12 volts to pertronix coil/conversion.
89 120amp external regulated denso mini alt with stock VR from the 85 harness
elect.fuel pump runs on the heater fuse with mech shut off switch.
not hard at all to fix one up and by-pass whats not used.