I am looking for information RE the diameter of the rear brake drums on an older 8.75" half-ton pickup rear end housing.

The B-Body rear we are using has 10"-diameter brake drums.

I have heard that some 1960s and 1970s half-ton pickups have 11"-diameter brake drums that can be swapped to the B-body housing, using the truck backing plates and wheel cylinders.

Does anyone know if this is true, or whether the trucks even HAVE the 11" drums or not?

Any information will be appreciated!

Bill, in Conway, Arkansas

Trucks, B bodies, C bodies, and E bodies got 11" brakes.

I recently sold a set of 11"X2-1/2" off of a '69 Roadrunner that I had used on my Valiant.

Also be aware that the offset on the backing plates is different than A body brakes. You will either need aftermarket axles or Moser can cut and respline C, E or truck axles. The ends of the axles are longer between the bearing and axle flange.

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Official Cookie and Mater Tormentor.

Typically trucks have 11 X 2 brakes although some with disc fronts may have 11 X 2 1/2, Some B and C bodies have 11 X 2 1/2 and a few C bodies have 11 X 3, all Imperials have 11 X 3 but the bolt pattern and hub are different. They generally all bolt up to 8 3/4 but heed Dennis' comments about the different offset on A bodies.

When we used to footbrake our super gasser we adapted Imperial brakes with some soft linings radiused to fit the drums. We had a 3/4' bore M/C and could generate 2000# line pressure. We could hold it on the line up to almost 4000 RPM but that was not wide open. The system isn't really made to perform under those conditions. Once we bent the rod that connects the M/C to the pedal and another time the brake shoe actually bent. Another problem was those soft linings tend to glaze up when stopping from 135MPH with rear brakes only.

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If you didn't drive it there, it's not a street car.

Thanks, guys, for all that good infformation.

The housing we are using is in a 1964 Valiant, but came out of a 1967 B body.

We have aftermarket (Yukon) high-strength axles for it that have to be cut to length (they have a long splined area.) They have Green bearings that were shipped to us in the same box with the axles, but are not pressed onto the axles, yet.

I am hoping that this "do-it-yourself" situation will give us some flexibility and latitude in fitting the larger brakes.

But, we're probably going to need new wheels with a different offset, because we have un-altered wheel housings and are running 9" slicks which only have about 1/2" clearance between the tire and the sheet-metal (it's not tubbed) as it is, with some custom-offset Stockton steel wheels,

A trans-brake is looking better by the minute... LOL!

Bill, in Conway, Arkansas

Bill, to get any room with a 28X9 under my '66 I had to roll a piece of pipe around the tire to spread the quarter panel out a little. It doesn't take much.

There isn't a whole lot of room under an early A body.

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Official Cookie and Mater Tormentor.

'Zilla,

These are 26 by 9's, (not 28's) but there's still no room. Makes we wish I had a first generation Valiant with the full-radius rear wheel opening.

Thanks for the tip RE the pipe. I may do that, too....

Bill, in Conway, Arkansas

I went through this with my both my 66 Cuda and 66 Valiant. Phoenix has a 6x26x15W slick that fits the Barracuda on "cop car" wheels. The tire is 7 inch wide, but right now it is on back order.
I tried a 9x28x15 on both the cop car wheels and a aluminum wheel. On one wheel (not sure, but think the aluminum) the tire hit the inside of the quarter panel. The same tire on the cop car wheel hit the spring. Tried a 1/4 inch spacer and it barely cleared the spring but just hit the quarter panel. I am thinking if the spring was moved inboard by using the Mopar Performance spring relocation kit (3/4 inch per side) it would work. Even more room could be gained by moving the spring into the longitudinal. I didn't want to modify the car, so I went with a smaller tire (8x23x13).

On the 66 Valiant we didn't mind "butchering" the car, so we just gave it full radius wheel cutouts.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

Thanks Charrlie. Ma Mopar didn't do us any favors when she designed thes 2nd-generation A bodies, with regard to tire clearance, did she? LOL!

We added some coil spring "helper springs" around the shocks and got the rear of the car up about an inch and a half. That helped.

We gave Cal Tracsm wich rase the back of the car when torque is appplied to the rear housing, so that helps.

I think we're gonna be okay if these 9"-wide Hoosiers will hook. We;ll see.

Thanks for the information!!!

Bill