Later disc swap question

They should line up about the same. If they don't and you need more clearance it's not a big deal. The whole spindle can be spaced out more or you can use a spacer between the wheel and hub. I have the spindles spaced out on my car for clearance. I used a 1/2" grade 8 nut as a spacer between the caliper bracket and steering knuckle. That and one washer gives me about 5/8" spaced out.

I discussed this with and engineer. He wanted to see a bare spindle. After looking at that he said a round spacer would be fine since the spindles contact surfaces are just the portion around the bolt, you're just extending the original surface. He agreed that a nut and/or washers would be perfect as long as it was held tight. Longer grade 8 bolts will be needed, and don't forget to put them head out so there is no interference with the rotor. You want grade 8 nuts/washers because they are hard material and won't crush.

There are at least THREE different spindle thicknesses. Many six cylinders have 1/2" narrower drum brakes than V-8s and have a bit thinner spindle base -- so that's two. Disc brakes have their own spindle, making three. There may be others too. Except for clearance between the spindle and tire or wheel there is usually no problem interchanging the brakes. If you keep stock wheels even that's not a problem. The only reason I had to space mine out (63 Classic six with 79 Spirit six discs) is because I needed deep offset wheels to run a Jag IRS and wanted to run the same wheels on both ends. My wheels have 2" more offset than stock (5.5" backset 7" wheels, normal 7" would have 3.5" backset) but I only had to space the spindle 5/8" out to have plenty clearance. Of course the big car spring seats are higher than the small car trunnions -- the lower end of the spring is just above the tire, not right beside it.


Edited by farna - Jun/02/2012 at 6:56am

Yes the spindles have different pads but the hubs or should I say bearing assy. are also different to take this in to acount.

if switching to disk brakes in would narrow your tire track . 1/2" per side

What you really mean is does the front tread change -- the distance from the center of one front tire to the center of the other. YES -- that will change by as much as 1/2" (more) on each side. It doesn't affect handling or steering geometry -- not enough to matter anyway. Front end alignment specs will be the same. 

Great, thanks.