My wagon. 87 dl NA automatic K 9800 speedo

The donor. 89 dl 5 spd wagon k 10042

On the way to the inspection station the odometer then speedometer fritzed

Swapped in the 89 board and it works and all the Christmas lights light up. Then go out like they are supposed to.

I want to get this tagged. Am I doing any harm by swapping boards?

One is the 2.4 fi and the 87 is a 2.2. Both chrysler.
speedo reads good enough for insp