Anyone know how to connect the factory a/c system into a Aem Ems-4? Know tuning settings has options for a/c settings. Any cons for not running the a/c system into the ecu?

Car June 1986 Magna MPI 5 Speed   Both pedal cancel button tabs are good Vac Hose Routing is good   87 Factory service manual says pre-87's require the speed control computer with the blue label. The one in the car is a yellow label part number MB509089. With this ecu the car can only be set by the resume switch and not the set switch. Once its on it then changes the speed into up and down issues "surging". Friend sent another speed control computer for a later year part number MB510816, car doe

that thing to 32810

Is there any other method to make up for timing chain slack besides using washers behind the plunger? On a block and head that were decked.