What Size Brakes Do I Have?

[RR Fan Dan]

I’m trying to buy brake parts but my car is not here to measure. 74RR rear drum size. Stock. 10” or 11”?

 

[Don Frelier]

Ask Carnac the magnificent

 

[RR Fan Dan]

Ask Carnac the magnificent
View attachment 1952858

What they weren’t a standard size?

 

[Vaanth]

I’m trying to buy brake parts but my car is not here to measure. 74RR rear drum size. Stock. 10” or 11”?

Standard rear drum brake diameter on a 1974 Road Runner originally equipped with a 318 engine was 10"x2.5". 11"x2.5" rear drum diameter was optional. B28 on the production broadcast denotes rear 11"x2.5" drum brakes.

From the 1974 Salesman Guide: (S = standard, E = optional)

 

[mobileparts]

The “ general “ rule is :
Small Block is 10 “ x 2 1/2 “
Big Block is 11 “ x 2 1/2 “
However ,
It could have been upgraded from 10 “ to 11 “ in the car’s prior history….
And with MOPAR , “ Never Say Never “…

Bottom Line is : Measure and be 100 % correct / Perfect ….

And , if you want QUALITY parts , P.M. me , as per forum rules….
Or , you can go to a parts store or internet for Chineseum garbage and regret it…..

 

[WileE]

^^^ Ask Craig, ya can't go wrong !