disc brake conversion

[Philster51]

I have a 71 F-250 2wd with drum brakes all around. I got the entire front end off of a 79 F-250 (GVW is 8100) with master cylinder, proportioning valve spindles rotor and calipers. The 79 front end is worn out. Can i change just the spindles, calipers, proportioning valve, master cylinder and be good to go? I am a little confused as if i need to rebuild the entire 79 front end and swap all the parts into my 71.
Thanks!

[69rangerf100]

im not sure about the F250 kingpins sizes but the F100 kingpin sizes are different

[FORDification]

It's always better to use the entire front suspension from the donor truck as an assembly, rather than trying to mix/match parts. That way if you ever need replacement parts in the future, you won't have to try to remember which parts are from the donor and which are original. There are also sometimes small differences (like kingpin size difference between GVW packages) that throws a snag into things.

However, having said that....with an F250 you don't need to swap spindles. The later disc brake parts bolt right onto the earlier drum-brake spindles, which is considerably easier than on an F100. If your kingpins are good, you've got it made. Swapping on the disc-brake parts shouldn't take more than an afternoon, aside from the likelihood of having to bend some new brake lines.

[fordman]

something else to consider if anyone ever uses a higher gvw front end under thier truck. the king pins got larger with the larger gvw of the donor. so you almost have to use the matched spindles and i beams together. because of king pin diameter.

[FORDification]

Again, that's just with the F100. On an F250, the kingpin size isn't even need for consideration when you're not removing it. Even if he had the lightest GVW '71 and the highest GVW donor, the disc brake components will still bolt up to the stock spindle.

[fordman]

yes that is correct. no need to bother with changin the spindles on the f250. only on the F100.