I too used the Comp, Eng. mid-plate withe spacer with it "same thickness as the mid-plate". The problem "IMO" it makes the flex plate bolts to short and these are .500 long bolts. And to compound the problem these are "slim headed" bolts! Normal headed bolts are to thick and interfere. Solution> I bought Pontiac flex plate bolts. their length is perfect. "Grind the bolt heads down to the slim type head bolt.