8.75 backing plates

For weight saveings I cut my backing plates too much.I need a pair of backing plates for 10 inche drums 2 inches wide.Car went from low 1.50 60 fts to 1.60s cause I cant hold the car at the line above 2500 rpm with a 4000 stall converter.Before I butchered my backing plates I could footbrake to about 3000.11.43 second car.Guzzi Mark