86' vs. 89' n/a

I'm sure they are interchangeable. I don't think that there are many differences between the two motors themselves, if there are any at all. If you mean you are putting an 86 motor in an 89 Mustang, granted they are both n/a 2.3's, you should be fine.
 
89' RICE COOKER said:
i thought there was a differance in the exhaust or intake ports? i cant remeber though. i guess ill see when my engine arrives.
There was an oval port head on early 2.3's, but I am pretty sure they went to the D port in the early-mid 80's.