alright, i have machined down the stock drum spindle as shown in the pic below and i am switching from stock drum fronts to stock disc fronts
http://i222.photobucket.com/albums/dd166/caudillj/Disc_spindle_dim.jpg

my question is... am i going to need to re-use this? what is it exactly? it goes in the hole that i machined down on the spindle
http://i222.photobucket.com/albums/dd166/caudillj/102_0741.jpg

You don't need the extension beyond the hex nut - cut that part off. The bolt then is used to secure the caliper bracket.

I just did the same thing last week.You probably need to get the correct bolt,I was fortunate that I had them.Because even if you cut yours the threads would probably be to long.:beers:

That's the "bolt" that used to go in the upper boss in the knuckle (the one you machined down). On a drum car, it retains the backing plate and the "pin" part is the upper anchor pin for the brake shoes, springs, etc.

You're going to nee "a" bolt (preferably grade 8) to mount the disc backing plate to that upper boss. You may be able to grind the pin down on that and use it, but I'm thinking that either the shank would be too long (like John mentions) OR the "shoulder" (part of the shank where there are no threads) will keep you from bolting it in all the way.

I'd use a grade-8 5/8"-18 bolt from your local (reputable) hardware store (at least, I think that's the thread size).

thanks guys,
i have the caliper brackets from right stuff and the dust shields... i also ordered 4 of these caliper backing plate bolts from ground up
http://i222.photobucket.com/albums/dd166/caudillj/bolt.jpg
do i need an additional bolt to replace this one
http://i222.photobucket.com/albums/dd166/caudillj/102_0741.jpg

Take a look at the thread depth in the hole. It may need to be tapped deeper to accept the mounting bolt.

thanks guys,
i have the caliper brackets from right stuff and the dust shields... i also ordered 4 of these caliper backing plate bolts from ground up
http://i222.photobucket.com/albums/dd166/caudillj/bolt.jpg
do i need an additional bolt to replace this one
<pic snipped>


Nope. And I think you have 2 extra bolts too. Spindle has 3 bolts that hold the mounting bracket. Upper bolt hole used to get that funky bolt in the pic, but gets replaced with the short ones you ordered above. Lower 2 bolts use the steering arm mounting bolts (through the steering arm, spindle, mounting plate, with locknuts on the end). Actually, now that I think of it, I think only one of those bolts (the rear one) goes through the caliper mount (the caliper mount doesn't extend all the way to the front bolt, so the front bolt just goes through steering arm and spindle)

JWagner does have a good point tho -- make sure the upper boss in the spindle is tapped deep enough for those new bolts to seat. You may need to tap a little deeper (?). Never looked at a machined-down drum spindle, so not sure how deeply they are tapped.

-T

Here's a pic from the backside off David Pozzi's site. (this is actually a Camaro spindle, but yours should be similar setup with different steering arms). New shorty bolts you order go in the upper "blind" hole to hold the caliper bracket (and dust shield?) on. Lower 2 bolts are the ones that you can see coming through and holding on the steering arm.

http://www.pozziracing.com/Media/1st_gen_spindle.jpg (http://www.pozziracing.com/brakes.htm#disc_brake_spindle)

thanks T,
this is the exact info i was looking for.
just to be clear though... the pic below is where i am right now... dust shield then bracket or vice versa?
http://i222.photobucket.com/albums/dd166/caudillj/102_0735.jpg

Hopefully this will help. Notice the seal between the spindle and dust shield.