Got just what you need - a complete cluster with the 125MPH Certified speedo and cop car factory oil pressure gauge. It's currently packed away in a tub for when we go to the Nationals. Pics at http://www.forfmjbodiesonly.com/classicmopar/showthread.php?t=23
Should be a straight plug 'n' go for Mirada's and Cordobas and possibly for the 79 St Regis cop car as well. Not sure but if you change the oil pressure sending unit to one for a gauge, the gauge should work as well since the wiring for the oil light is already present.