When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I have a 9" out of a '66 pick up. and I was going to sell the center section to a guy with a '78. Are the splines and axles the same, or are they different?
The axleshafts are different, 1957/67 F100's use the same 28 spline axleshafts. 1968/72 F100 is different than 1957/67, could have 28 or 31 spline axleshafts. 1973/79 is different than 1968/72.
1973/79 F100's, 1975/79 F150's could have either 28 or 31 spline axleshafts.
The only way to know is to either to pull an axle, or get the axle code from the ID tag and post it here.
The other issue is the axle bearing. Some 1974/79's use the same ball type axle bearing and separate seal as 1961/73's.
Some 1974/79's have a tapered roller axle bearing/seal combination. The only way to know, is to pull an axle.