71 Dart 408 vs 71 Duster 410......

flow data on eddy heads by IMM 2.055 intake 1.60 exhaust.

.100 72/55
.200 148/108
.300 204/149
.400 247/181
.500 278/202
.550 285/207
.600 292/210
.650 292/211
.700 292/212