Recently purchased 1971 Plymouth Duster. Original 318 car, previous owner replaced with a 1970 block 340, 10:3 compression, roller rockers ,ported heads, 2.02 valves, 540 lift hydraulic cam and 750 Holley carb. 904 trans includes a 8 in. turbo action converter. 8 3/4 rear axle with 3.91 gears...