This only applies to the 330 Heavy Duty engine used 1964/72 and the 361 & 391 engines used 1964/78.

Originally (1964/72) there were four FT engines: 330 2V Medium Duty, 330 2V Heavy Duty, 361 2V and 391 4V.

The 330 Medium Duty is FE based, the 330 Heavy Duty used 1964/72 is based on the 361/391.

The 330 Medium Duty used 1965/67 used the FE 352 crank (C4AZ6303L), this same engine used 1968/73 used the the 1968/72 FE 360 crank (C8TZ6303A).

And...the so called 330 Heavy Duty engine used 1974/78 used the 1973/76 FE 360 crank (D3TZ6303B).

Ford confusion: Ford dropped the 330 Heavy Duty engine in 1972, then...called the former 330 Medium Duty the 330 Heavy Duty!

Bottom Line: The 330 Heavy Duty engine used 1973/78 is nothing more than the former 330 Medium Duty engine used 1964/72.

The OP's VIN: F61DVY40884

F61 = F600 2WD

D = 330 Heavy Duty (formerly the 1964/72 330 Medium Duty)

V = Kentucky Truck Assembly Plant

Y40884 = 1977

MODEL Code: F611 = F600 2WD, 20,200 lbs. Gross Vehicle Weight Rating.

F611D = No such thing, the D is part of the following BODY code.