joe_padavano

That looks right. It's the Raybestos 580120 (or equivalent), and your numbers are the same. Hopefully the holes for the redrilled lug pattern will fit with those three mounting screw holes.

joe_padavano

OK, an update on using the Cadillac CTS rotors. The center bore needs to be opened up to 3.463-3.467 inches. The original hole is about 2.7", so there's plenty of meat. The lug holes need to be redrilled to 0.638-0.640 inches on a 5 inch bolt circle. There appears to be plenty of meat at the three attaching screw holes so that the lug holes fully envelope them. Use Dorman 610-219 wheel studs. The rotor goes on the back of the hub, so be sure the mating surface on the hub is clean and flat. Might be worth going over it lightly with a flat file. The studs pass through the rotor and the knurls hold them into the hubs. You MIGHT have to slightly flatten one side of the head of each stud to clear the ID of the rotor hat - it isn't clear if that ID is large enough or not. This is no big deal. It might also be smart to have the rotors skim cut after assembling them to the hubs just to be sure there is no run-out.

eric66

I'll pick up a set next weekend will post how they turn out.You got any pictures of your Accomplishment. Thank you For your effort.

imcgm

where are yours from eric66?

imcgm

Joe, i found reference to Raysbestos 6041 and 6043? idk...

joe_padavano

I don't know where you got that info (might they be the rotors used on the Scarebird conversion?), but those are Ford LTD REAR rotors that are only 11.5" in diameter and about 0.945" thick. The stock 69-70 Olds rotors are 12" in diameter and 1.25" thick. The Caddy CTS rotors are 11.92" in diameter and 1.25" thick. Obviously, the height of the rotor matters also (backside to front mounting face), and the CTS rotor is nearly the same as stock. I don't know what that dimension is for those Ford parts. The stock Delta rotors fit to the backside of the hubs.

I should clarify that the CTS rotors I suggested are intended to be replacements for the Olds factory rotors and only work with the factory DISC BRAKE hubs and spindles and caliper brackets. You cannot use them for converting a drum car using drum spindles and hubs.

imcgm

has anyone bought the Scarebird set up? it looks good to me...

https://scarebird.com/index.php?rout...product_id=173

hmmmm

joe_padavano

Quote:

This conversion uses 1976 Eldo rear rotors and calipers/pads to complete the wheel assembly.

Your call. Those Eldo rotors are only 11.0" in diameter and 1.20" thick, so A-body sized but slightly thicker. This is one of the problems I have with Scarebird - their systems are always undersized as compared to what the factory used. Your call if replacing 11" drums with 11" disks is worth the effort and cost.

imcgm

imcgm

so Joe if I may sum up. you recommend using a full size 70 olds for the front disc donor set up, along with the CTS caliper trick and away we go?!

thanks for all your patients,
Mike
<<<admitted novice>>>

Koda

I've never thought much of the Scarebird system. One needs to look at the forces involved, not just the geometry.

Dude was on here a couple months back going on about how his stuff will fit SSI wheels and no other disc brakes will. When we pointed out that MOST SSIs will accommodate factory discs, he got all quiet then put up a parts wanted ad for a particular wheel. I think he then abandoned the project, and us, after seeing no profit.

For the record, for A body Olds, factory disc will work with all SSII, all SSIII, and all SSI except for the 14x6 66-68 chrome rim.

joe_padavano

Yes. The OEM disc brakes from a 1969-70 Olds full size will bolt to any 65-70 full size. The calipers, pads, hoses, bearings, seals, etc are all readily available. The problem with the used OEM discs up to now has been the non-availability of replacement rotors. These CTS rotors are the first that I've found that are close enough to work with only minor machining. There was a vendor advertising "new" replacement rotors on ebay a while back. I'm sure he started with these CTS rotors and did the machine work.

joe_padavano

Yeah, and at the risk of veering off topic in this thread, I'm really skeptical of the vendors who sell A-body disc brake kits that supposedly fit the 14" drum brake wheels. These aftermarket kits use Pinto-sized 10" rotors and the small metric GM calipers with the 2 3/8" pistons and smaller pads. This is not an upgrade from the stock drums as far as braking force is concerned. The OEM A-body discs are 10.75" diameter and the calipers use 2 3/4" pistons.

Now back to our originally scheduled thread...

boese1978

I used a Scarebird kit on my 68, totally happy with all.

eric66

O'Reilly auto parts , part# 580120rgs

imcgm

@eric66 did you pick up a set of rotors? if so how did it go?!

eric66

Not yet been busy at work will get on it when I get time will post pics on the out come��

imcgm

@joe_padavano soooooooooo...do we change spindles on this job also? thanks Joe and everyone else!!!

delmontcrusier

I started this thread a long time ago and decided to come back read what has been posted since I have been mia from here for awhile. The funny part is I never did update to disk. I should but still have the old drums going. The car sat for a few years as life throws curve ***** and the whole mess over the last two three years. I finally blew the old dust off and got it out and driving again. She looks a bit ruff now days and needs a bit of a repaint. The clear coat is basically gone. Still I am happy to be out driving it again

Jaybird

I haven't changed over to disc brakes either. I was curious if it was possible. My car was manual drum brakes. I was able to upgrade to power brakes, thanks to my parts car. They work well, just stay out of puddles.
Meanwhile, I'm just about ready to swap out my open 3.08 rear end for a limited slip 3.08 rear end that I happen to have.

delmontcrusier

Go figure I updated this thread thinking about brakes still want to do something as I can never seem to get them front drums adjusted to stop evenly. But now I have to look over the motor as it made some ticking knocking noises then seemingly went away. Many say most likely just a sticky lifter. But I will have to check it over thoroughly. I don't want the possibility of a cast iron paper weight.

griffey57

My 57 olds has power drum brakes and they work beautifully

delmontcrusier

I have the olds back out this year and in part due to my truck being down and it is that time of year for it. Seems I did some minor maintenance and so far so good. I'm of course referring to the unpleasant sounds coming from the engine. Now aside from that I now find that scarebird company has been bought up or sold off as you will and the kit seems to be unavailable. I know some frowned on many of the brake conversion kits. I still need to do something with the ol blue beast. But not sure what I want to do. Prior to this car most my vehicles had disk in front drum in back . I never seem to get these front drums adjusted correctly. For me one grabbed before the other. Mind you it could be a simple overlook as easy as installing a new flex brake line on the other side. Possible restriction in the line from being old etc. But then again I am used to disk on the front of vehicles. My plan always was to figure out a disk kit of some sort one was ssbc 123-13 I believe that is the correct kit. But funding has not been available long enough to inquire and buy said kit. I also would keep the old original parts so if I was to ever let go of my car the next owner would have the option to go back oem if wanted. Not saying the old blue beast is going anywhere lol.

Vistabrat72

As many here have said, older cars with drum brakes do not stop as fast at higher speed repeatedly - stop and go. At cruising speed around town or slower secondary roads, they are fine, just be aware your stopping distances will still be not as good as new cars. watch your distances, it is hard these days with people always crowding into your safety zone. Having said this, the best way to keep the drums working well is to replace brake hoses, wheel cylinders or at least rebuild the old ones, make sure the drums are the exact same diameter in front. In other words, if one needs to be turned - within spec limits - then do the other one. Be sure your wheel alignment , control arm bushings etc are in proper adjustment or state of repair. For the time being, this has helped our 66 Ninety-Eight LS stop straight and true with no antics. The car is getting a set of 1970 disc brakes, have the main components, saving up to get the CTS rotors and the machining of them. Hope this helps a bit. Regards, Howie.