It's interesting you mention 2.5 Lumina. Crank sensor in the block attached to the ICM for DIS
Here is a quote from 1project2many from my first thread here.

If you were designing from stage one you could select the 7727 / 7730 ecm and use a calibration from a 91-92 Lumina 2.5 TBI to get an even later generation of ecm but since the 165 is in place I'd probably stick with that.