1969 mach 1 M code 351 Winsor Acapulco Blue DSO 33 Detroit. To the best of my knowledge: All 351 engines in 1969 were Winsors. The 351 Cleveland was still being developed and debuted in 1970. If, in 1970, the factory ran out of the newly produced Cleveland, then a Winsor would be substituted into the car, so some 1970 H and M code mustangs came with Winsors. Cleveland did however debut in 1969, the heads were adapted to the Winsor based 302 block (G code) for the Trans Am races. These cars were winning in the 1st half of the season until a crash took the Boss cars out and the '69 Trans Am season went to Z28. The '70 Boss cars however did not crash out. The 302 blocks were used to meet the 5.0 L Trans Am requirement, the Cleveland heads are what won the races and define the old Boss 302s. Its a shame the beautiful '69 mach 1's didn't have Clevelands installed from the factory.
