[242177P]

Originally Posted by jerry455

... 1LE rotor. ... It was the same wagon rotor only with the 4 3/4" bolt circle instead of the wagons 5" bolt circle.

A minor, and not so minor, detail has been overlooked. B-body rotor was 1.25" thick, like the pickup trucks. 1LE rotor was 1.10", which meant you could re-use your F-body calipers. HTH.

[Formulajones]

Originally Posted by 77 TRASHCAN

The aluminum 9-1/2 drums were on many GM makes. It might be difficult to find 2 good used ones. I've not known any aftermarket brake manufacturers to make them in aluminum. I'd run them on my TA, if I could find 2 usable specimens...

I currently run D153 pads on my stock calipers. These pads were used on 3/4 pickups in the 80's. 3/4 tons had light and heavy duty brakes. The D153 pads are the light duty pads.

I run a pair on the Chevelle. There was a company at one time reproducing them. I'll have to dig into that and see if I can find the info.

[Formulas]

national parts depot for aluminum drums

Item # C-5809-3CA
Brand: Cardone

[242177P]

Originally Posted by Formulajones

I run a pair on the Chevelle. There was a company at one time reproducing them. I'll have to dig into that and see if I can find the info.

IIRC, it was Dennis Kirban. HTH.

[Scarebird]

Originally Posted by Skip Fix

...I've been lucky with the 81 TA setup on my 78 never had much issues over 30 years with it. Adjustable prop valve and I think the silicone fluid keeps the ratchet working better.

Best thing for the 79-81 WS6 calipers and the Eldo units is EVERYTIME you shut off the car, engage the parking brake.

[hgerhardt]

Originally Posted by 242177P

A minor, and not so minor, detail has been overlooked. B-body rotor was 1.25" thick, like the pickup trucks. 1LE rotor was 1.10", which meant you could re-use your F-body calipers. HTH.

The last B-body rotor that was 1.25" thick was the '76 and earlier. The '77-'96 B-body rotors were 1.10", both for the 11.5" and HD 12" dia. My '89 9C1 Caprice had the 12" x 1.1 rotors with a 5x5.0 bolt circle and 1/2" studs.

The cool thing about the 1LE rotor is it's the HD 12" B-body rotor, but with a 4.75" bolt circle, so a hybrid.

[64speed]

I have the Wilwood D52 calipers on the front that accept stock size pads. On the back I have a Ford 9 inch and have the mid 90s Ford Explorer discs. With hydroboost the car stops GREAT. It has the parking brake in hat style rotors. Parking brake cables are gonna be a pain in the ass though because the wilwood kit that Quick Performance sells for conversion is universal.

[Formula8]

As others have said, I would start with what your intended use is and from there, determine why your current set up is coming up short. If it is just a stock(ish) appearing driver and you are just looking for improved stopping power, you are unlikely to find it in rear discs. I would probably invest in things like the master cylinder, brake booster, adjustable prop valve and dialing in the pad selection.

That said, I have a different theme going with my car and wanted the brakes to match that so I ended up with C4ZR1 13" fronts and 12" LS1 rears. That was quite the improvement but probably at least half of that came from a dual diaphragm booster, C3 master and Wilwood prop valve. Most of the rest of the improvement was from way aggressive GMPP pads that had an incredible initial "bite" but produced an equally incredible cloud of brake dust all down the side of my car and wheels. I swapped them out for a set of Powerstop Z26's and that eliminated the dust but also eliminated the nice tight initial bite. I would have a tough time recommending that pad.

What I am getting at is I would do some diagnosis on what you have and get that in proper order and balance and then decide if you need to make some changes. I am not sure if I agree with the "locking a tire" oversimplification as for most, a lot of it has to do with the "feel" of the pedal and many of these 60-70's era brakes are going to struggle to lock up a modern "pro-touring" type/sized radial tire much less feel like modern car.

[Skip Fix]

'96 Police Caprice and Impala SS 614 pads will also fir D52 calipers if you feel the need for a larger pad.

Speedway also has a 1LE rotor with 7/16 studs vs the metric studs.

[Tarl]

Another cool thing about the The cool thing about the 1LE rotor is it fits under a standard Rally II wheel. Loved these on my 66 Lemans, wish I could put them on my 68 Firebird.

[Formulajones]

Originally Posted by 77 TRASHCAN

The aluminum 9-1/2 drums were on many GM makes. It might be difficult to find 2 good used ones. I've not known any aftermarket brake manufacturers to make them in aluminum. I'd run them on my TA, if I could find 2 usable specimens...

Here ya go in case you missed it. These are exactly what I run on the Chevelle, and to my surprise they currently have them in stock. Formulas actually found these listed.


https://www.npdlink.com/product/drum...than-mo/206310

[Formulas]

One thing i have noticed as they age rear drums do not work as well as the first day you put them on and are adjusted perfectly even with perfect hardware / adjuster, they just seem to lose effectiveness as time goes on
thats just something that is eliminated by disc

I have bumped up against brake limits a few times in my life not a bad area to upgrade unless you drive like gramps 100%

[Skip Fix]

Driving some curvy CA roads my 78 TA's stock disc drum had some serious fade!

[JLMounce]

Originally Posted by Skip Fix

Driving some curvy CA roads my 78 TA's stock disc drum had some serious fade!

Yes, this is one of the areas where having that rear disc really starts to make sense. If you need repeatability, discs are the way to go.

The stock type 11" front and rear disc with aluminum calipers instead of the stock iron stuff will provide really great fade resistance for your standard street performance stuff on typical rubber. With upgraded pad compounds that work with higher heat, that same brake system becomes pretty capable in non-competitive auto-x as well.

Once you start putting the car on R compound tires in auto-x situations or especially on big open tracks. That's when having the big 14" rotors starts to become not only beneficial, but in some instances necessary.

[Skip Fix]

Mount Umunhum Radar Station Road off Hicks Road looking over Santa Cruz CA!

[ZeGermanHam]

Originally Posted by 64speed

Parking brake cables are gonna be a pain in the ass though because the wilwood kit that Quick Performance sells for conversion is universal.

I just installed the Wilwood universal parking brake kit a week ago. It was super easy and only took me about an hour to install. Works well.

[leeklm]

Did not read every response here so this may have been mentioned... if you do choose rear disc, do not haphazardly piece it together. Be sure to use the right combination of verified parts such as master cylinder, prop valve, brake line sizing, calipers, e-brake, etc. The wrong combination of parts can leave you wishing you left your drums on. Ask me how I know....

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