Information compliments of Bill aka the NumberDummy...
"1971/77 steering wheels are 16 1/2" in diameter. 1978/79 steering wheels are 16" in diameter with manual steering, 15" in diameter with power steering.
1961/62 F100/250 2WD: The 3 spoke steering wheel is the same as 1960/62 Falcon/Comet: 17" in diameter.
1963/66 F100/250 2WD & 1967/70 F100/350 2WD/4WD: The 3 spoke steering wheel is the same as 1963 Falcon/Comet, 1966/73 Bronco: 17" in diameter.
1961/66 F100/250 4WD's and F350/600's used a 4 spoke steering wheel: 18" in diameter."