The duffs kit is like three times as expensive as most others, is it really that much better?
Well...I don't know if this is a serious question or not... But, let me explain**-
The Monster Disc Brake System from Duff's:
1) First of all, there is no other kit on the market like it. Your statement of "three times as much" is inaccurate both in it's quantifier, and in its implication that it is the same as "most others".
2) Duff's manufactures their own steering knuckles and caliper mounting brackets (to original Ford mounting specs). You cannot get these anywhere else...unless those are Duff's, too.
A) The steering knuckle castings are a redesigned, and strengthened, version of the original Ford disc brake knuckles. However, when Ford changed to disc brakes, they also opened up the width of the tie rod connection on the knuckles (steering arms). This width increase made it incredibly difficult to run anything wider than a 7.5" wheel, even with perfect backspacing. Otherwise, the tie rod contacts the inside of the wheel. This forces you to use spacers, move to 16" or larger wheels, or just live with a narrow wheel.
The Duff steering knuckle puts the taper back into the arm. This allows you to run 15x10 wheels without contacting the tie rod.
B) 0.030" is added to every part of the web and anywhere in the casting (as long as it does not prevent mounting original components). Just stand a Duff casting next to an original knuckle. The difference is obvious.
C) The steering arm is machined to a 3/4" through-bore. This allows you to bolt-in a heim steering system without drilling the knuckles. But, they include tapered bushings with the kits if you want to run stock tie rod setups.
D) The hub and rotor assembly are Ford specific units, not redrilled "other" assemblies.
E) The caliper mounting brackets are new castings. They accept stock 1976-1977 Ford Bronco brake calipers, hoses, and pads. Not only are these included in the Duff brake systems, but replacements are readily available at any auto parts store of your choosing.
F) Duff's offers the "T-Bird Upgrade" and does the necessary machining for you. It also includes custom hoses to adapt to the Bronco installation. These items are offered as replacement parts as well. Same pads, 20% more surface area of clamping force.
3) Duff's also includes a master cylinder that is matched to your system needs. This is far more than just "bore size". It involves chamber size; orifice size; combination or proportioning valve; engine vacuum; disc/disc or disc/drum; parking brake or no parking brake; etc. Duff's stocks at least half a dozen, custom-spec'd master cylinders to make the system operate to its fullest potential.
4) In addition to the brake components, the Duff system includes new, correct spindles; spindle bearings; the hub and ball joint tool; HD ball joints; all the seals and bearings from the knuckles out; new spindle nuts; mounting bracket; and all hardware. And, again, all of these replacement components can be purchased locally in the future (although the Duff replacement prices often make it less expensive to get from them than to purchase yourself).
5) All of this is offered at a price less than the cost of basic disc brake "conversion" for almost every "muscle car" ever built.
On top of all this, you get the best tech and troubleshooting in the business. Although you may not enjoy the process, you get access to someone who understands true diagnostics...and can walk you through it. Not just a "well, maybe you should buy this...or try this..."
And, to top it all off, Duff's is now a distributor for hydroboost, by Hydratech Braking Systems. They even have their own, Bronco vendor exclusive, "no mod" mounting bracket for hydroboost...an industry first. It does not require cutting the firewall to mount (specific configurations necessary).
Hope that helps clear up any misunderstanding about "comparisons".
** Disclaimer:
Not only do I own my own shop, building Broncos that you can actually enjoy, I am the lead tech for James Duff Inc.
I, personally, spent over three years developing and dialing in the Monster Disc Brake System for Duff's. Recently, James Duff invested thousands of dollars in objectively testing every braking configuration known for Broncos: from bone stock, 4 wheel, manual drums; all the way to hydroboost, with 4 wheel disc brakes and tall tires. And, they video recorded it for proof, posterity, and just plain fun (Who doesn't love to see a 4-wheel lock up and slide on 35's!).
I have been a builder for over 30 years, including hot rods, street rods, rat rods, bracket racers, minitrucks, lowriders, and, of course, Broncos. I am also an enthusiast who cares more about performance than looks.
I received personal training, and a professional endorsement, from Paul Clark, owner and founder of Hydratech Braking Systems.
I received no compensation or accommodations for this post.