the 6.3 is the absolute fastest but the upholstery is so old good parts few and far between.the best of the 6.9's were produced in the last 3 mths of 79 and were european.standard hp was at least 295 and those last 300 cars had abs brakes[if there was ever a car that needed abs brakes the 6.9 is it] i believe that the vin#'s were in the 006300 range[last 6 digits]you stand a better chance of finding good seats or parts for the seats with a 116 body and the parts for the hydraulic suspension were used on a number of 126 bodies. david poole european performance dallas tx.