1991 Dodge B150 RamVan

SummitRacing shows two rear drum size options, 11x2.5 or 11x3.

Is there a compatibility/sizing concern to be aware of or can I just get a 3" wide set and not worry about compatibility?

 

You have to match the width of your brake drums. This means you'll have to remove one drum and measure what's existing. The 2 sizes are not meant to be interchangeable.

 

Just exactly is the measurement taken???

 

Bummer. I wanted to get replacements before taking anything apart...

What would happen if i got a 3" shoe/drum combo and it was meant to take 2.5"? Would it hit rim or what?

PS - Alloro > Your responses have been helping me for years. I owe you some beers if ever in Portland Oregon.

 

The back edge of the drum would hit the backing plate and the front would not reach the axle hub.

OTOH, if you got the 2.5 and needed the 3" (assuming they'd fit) then your rear braking power would be reduced around 15%