4"to 41/2 what backing plates

[moparraceman]

83/4 with 4" bc drilled the axles to 41/2" bc new studs ,drill the brake drums to 41/2 bc what backing plates can i get to use that has 41/2 bc ? with the set up i have now thanks

 

[Professor Fate]

The backing plates need to be matched to your drums, and since what you have are actually 4"BC drums from an A body, you need the A body backing plates. And A body brake hardware. All you did was redrill the standard axles and drums, nothing else changed.

 

[Projectile Dart]

As stated by @Professor Fate, sounds like you just re-drilled A body axles so you would need to stick with your A body brakes and just re-drill the drums to match.
If you had bought aftermarket axles then about 99% of them require brakes that would have been originally found on original BBP cars (B/C/E bodies...)

 

[jos51700]

As stated by @Professor Fate, sounds like you just re-drilled A body axles so you would need to stick with your A body brakes and just re-drill the drums to match.
If you had bought aftermarket axles then about 99% of them require brakes that would have been originally found on original BBP cars (B/C/E bodies...)

This. Aftermarket axles are spaced out a wee bit to allow the wider brakes, and then you just rob the whole mess from most any other RWD Mopar car. Re-drilling axles means you now have a custom machined wear component: The rear drum. (granted, it'll take a lifetime to wear it out)

 

[moparraceman]

thanks

 

[72bluNblu]

A visual on what the issue is...

Small bolt pattern A-body axles have a different flange offset than the big bolt pattern axles. So the backing plates for SBP axles also have a different offset than the BBP backing plates.

If you use re-drilled axles, you must re-drill your drums. This is also true for some aftermarket axles that have the BBP but have the SBP axle flange offset.