I guess you are wanting to use the A9L and its matching harness in your Speed Density car? As you've found, all of the chassis to engine harness plugs are different between the earlier and later cars (A9L is a late model mass air car, not a cobra). A MUCH simpler option is to leave your speed density harness in place, plug the A9L computer into the SD harness, and add the 3 wires for the mass air meter to your existing harness. If this sounds complicated, then its DEFINITELY your best option since the alternative is repinning the whole chassis harness.