Okay when I am rewiring the vehicle for MPFI am I just playing with the Wires coming out of the dash harness plug on the ecu or the actual ecu pins themselves?

I am going to be using a p28 ecu and a ecu adapter from locashracing.com... so in order for this to work with the D16Z6 engine I first need to rewire my harness to accept MPFI- correct? After I (assuming I am just cutting and splicing/rewiring the dash harness and plug) rewire my car for mpfi all I have to do is plug my harness into the adapter pigtail harness and then into my p28 ecu right? No having to rewire the p28 ecu?

Thanks