You could be right, although i was looking for info on the R280 and 286 at the time and the R280 specs tallied with my R280 measurements.
Mick


69 Dart GTS 440 mopar .590 cam, Edelbrock heads, 3200#
best et 6.45, 106.78, 10.14, 132.88 mph, 1.47 60ft
best 60ft 1.36