1977 Ford F-150 gear ratio?

My truck had a 351M that puts out around 300-320 HP it has a 3spd auto trans, ford 9in rear what are the ratios per gear?

Count and see. That 351m did not put out anywhere near that stock. It was a detuned smogger

It probably has a C6. 1st is a 2.46, 2nd is 1.46, and 3rd is 1.00

Also bone stock the 351M has about 150-160 HP. It's nowhere close to 300-320 HP even if it's been warmed over.