[saf-t scissors]

And keep in mind that the stock calipers and pads AND rotors are pretty damn small. The 78/79 Bronco stuff is even worse. (In other words, don't bother with stock calipers)

There's a writeup on ProjectBronco.com somewhere in their forums that I can't find at the moment. It basically boils down to this: use mid-70s Thunderchicken calipers with the straight D44 axles. The caliper is maybe 3-1/2" dia vs 2-1/2" dia for the stock Bronco stuff.

I'm also not really sure why you'd need to swap to D44 brake lines, either. You could actually keep your 4WABS with the straight D44 (and your stock brake lines) IF you wanted to.

The prop valve on the earlier RABS-only Broncos is a 2" long 7/8" dia cylinder mounted on the rear M/C output. I don't know if the 4WABS trucks still use these or not.

 

[saf-t scissors]

Do you already have the D44?

I'll tell you this much flat-out (and this really has nothing to do with your question, but it's going to help, I promise):

Don't incrementalize. Save your money. If you're holding off on putting larger calipers with the straight D44 because "you're planning" on going with 8-lug fronts and a 10.25 out back, you're only a stone's throw from yanking the D44 in favor of a D60. A few broken u's or busted ball joints will help you make up your mind, I'm sure.

How long was that straight D44 under Dave Blue's truck? Can't have been much longer than 3 or 4 days by my estimates.

And yeah, I agree about ditching the 4WABS. Rob Ellis did it on his truck (351/E4OD 94ish model) with no ill effects that I have seen or heard. I just wasn't sure what your game plan was.