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Discussion Starter #1
Hey fellas-

Anyone know of any compatibility for a disc brake swap on a 68 Firechicken? I am going to drop in a LS1 or LS2 w/6 speed, and figure that the drums should go.... I know that many cars mid 60's to early 70's GM will work, but I was talking to a guy who did a 67 Chevelle convertible, and he swears that the discs, steering box and power booster out of a mid 80's RWD Cadillac will work.... the junk yard that I've been going to doesn't have any Caddies that old.... the newer stuff isn't even close- spindles are at least 2" taller.... I know that you can buy an aftermarket kit, but that takes all of the fun out of it, doesn't it? Anyone can open their wallet- I'm trying to do it "old school style," so to speak...

Matt
 

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The wrecking yard way to get discs on your Firebird is to use the factory-style spindles. These are the same for all 64-72 A-body (Chevelle, Cutlass, Skylark, LeMans) and 68-74 X-body (Nova and derivatives) as well as 67-69 F-body. These cars use spindles with bolt-on steering arms and caliper brackets. Use the 69-up single piston caliper design brakes since the early (67-68) four piston calipers are rare, expensive, and prone to rusting in the caliper bores. If the spindles come from an A-body you'll need to swap the steering arms for your original ones. The A-body uses front-steer (linkage in front of the wheel centerline) and the F-body and X-body use rear-steer (linkage behind the centerline). That also means that the 80s Caddy spindles (as suggested by your friend) will work on his Chevelle but not on your Firebird. Note that this B-body spindle swap is popular because it provides bigger brakes but it also requires different upper control arms and tie rod ends as well as different ball joints when used on an A-body.

Unfortunately, the factory disc spindles are almost impossible to find in a wrecking yard anymore, so depending on how long you want to keep looking, you're stuck with ebay or aftermarket parts. If you go that route, you can find kits that bolt to your existing drum brake spindles, which might be easier.
 

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Discussion Starter #3
true...

yes, it's true-- there simply isn't much left in the junk yards anymore-- most of these cars were long ago canniballized.... do you have any experience with any certain manufacturer? There are several options- never having gone this route before, it would seem to me that to a certain extent, you get what you pay for ... ie the brake kit for $599 or the one for $999. Any idea if this holds true for these kits? Thanks for the good info---
 

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blacktoothgrin said:
it would seem to me that to a certain extent, you get what you pay for ... ie the brake kit for $599 or the one for $999. Any idea if this holds true for these kits? Thanks for the good info---
no, not at all. With the big dogs you are paying a lot for marketing, mucho overhead. What size rims do you plan on using?
 

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Discussion Starter #5
Disc Brake Swap

I have a really nice set of original Rally II's, but I think those would be better used on a stock, original car.... I think it would look sharp with maybe some 16's... something with a lower profile tire (not super low, think Eleanor...) Also am not sure if I am going to use drop spindles... probably have to with larger wheels?
 

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Discussion Starter #7
disc brake swap

Yes- the geometry is significantly different, but that's about all I know about using drop spindles... (haven't done any research yet) Because of that, I am leaning towards staying with what is stock simply because I know how things will turn out...
 

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Discussion Starter #9
disc brake swap

I just checked out their website.... I'll give 'em a call and see if they still do.... thanks for the tip! Is there anywhere where I could get the specs for machined drum spindles? There is a machine shop where I've had parts for some of our paving equipment machined, and I'm certain he could do it... Acactually, I guess if a guy acquired the entire disc brake assembly with all bearings and took it to a machine shop, they could easily figure out what had to be done...
 

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The two-piece spindles use a bolt-on caliper bracket. The discs and drums use the same bearings so there's no need to do any machining there. There are three bolts that hold the drum backing plate on to the spindle. The bottom two are through bolts that also hold on the steering arm. The top one is a tapped hole. The caliper brackets attach to this top bolt and one of the two steering arm bolts, depending on which side of the car its on. The top bolt is larger for the caliper bracket than the drum backing plate and this is the only machining required to change a drum spindle into a disc spindle. Of course, you'll need to buy the caliper brackets, but these are available as repros. The rotors are available from any auto parts store, as are rebuilt calipers, hoses, and pads. The repro caliper brackets are for the single piston calipers offered on the 69 cars, so just ask for calipers, rotors, pads, hoses, etc for a 69 and you're good to go.
 

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Discussion Starter #11
Disc brake swap

As I was reading your post, I had a Homer Simpson "DOHHH" episode.... I never even thought that these parts were available over the counter. Thank you for all of this info- it makes sense. I have a drill press, so drilling out the hole isn' t a problem at all. Joe- you rock. Thanks again! :thumbup:
 

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Might post over at www.camaros.net/forums or www.stevesnovasite.com/forums . One or both of those used to have some info on machining drum spindles, but both have had server changes in the past couple of years, so the old posts may be gone. I think they said to machine 0.610" off the anchor bolt boss so it's parallel to the plane of the lower holes and re-tapping the hole for the bracket bolt, but DO NOT TRUST MY SOMETIMES FEEBLE MEMORY FOR THIS INFORMATION.
 

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Discussion Starter #13
Disc Brake Swap

I feel your pain- I can't remember if I had coffee this morning... I will check out these sites, and post if I can't find any info in the forum search.. Sounds like it should be a pretty easy process- the measurements and geometry are the critical parts. I have an excellent machinist who can take care of this easily. Thanks again for all the info!
 
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