I've just been looking through some parts i have and would you believe i've got another herbert roller , it's a D6C, the card says.625/.625, 275int/283 exhaust at .050 on a 108 lobe centre.
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