Gear's

i had almost identical combo in a 68 4dr dart best run with a 2.76 geared 7 1/4 was 13.34 @104 i find that amazing that the combos ran so close together!! i swapped to 3.91's and went 12.76 but mph stayed @104 and i did have a 750 holley. im sure you combo will wake up with a bigger carb. but i would think with 3.55's and the 600 your good for a 12.90 run........ and i would think most of you gain will be out of the hole cause that 600 is gonna restrict top end power.