swaping motors do i need the wiring harness?

[bigfltruck]

so im swaping a 89 bronco II 2.9 v6 with no egr into my 87 ranger that has a 2.9 v6 with an egr. im swaping computer from the b2 into the ranger and keeping the throttle body from the ranger. im wondering if i need to swap the engine wiring harness and if i do will it just plug into the existing harness.

 

[IMenriched]

so im swaping a 89 bronco II 2.9 v6 with no egr into my 87 ranger that has a 2.9 v6 with an egr. im swaping computer from the b2 into the ranger and keeping the throttle body from the ranger. im wondering if i need to swap the engine wiring harness and if i do will it just plug into the existing harness.

Off the cuff...I'd probably use the newer harness as well. there might be subtle differences in the harnesses, that might head off some frustrations farther down the road.

 

[bigfltruck]

that is kinda what i was thinking but was worried about if it was as simple as a plug in. im working on takeing the whole harness out of the b2 so i can see what is involed in the process thanks for your input.