'69 Drum to Kelsey Hayes Disc - Does it change the Backspacing?

[69cudaownr]

Guys, I am switching from SBP drums to SBP Kelsey Hayes discs from a 69 donor car for my 69 car. I'm ordering new wheels too and have to figure out the backspacing. I don't see why there would be a difference in distance between the hub and the wheelwell whether it's drum or disc. Has anyone had experience with that?

 

[Kendog 170]

I think it's the same. JMO

 

[toolmanmike]

I think it does. The disc brake cars have a wider front track than the drum cars. Let me see if I can find the spec.

 

[toolmanmike]

I think it does. The disc brake cars have a wider front track than the drum cars. Let me see if I can find the spec.

Sorry, ran out of time. A roofing contractor is due here any minute.

 

[66fs]

They used the same wheels from the factory for disc or drum, but don't know the exact difference.

 

[jazak5]

why they only went with 5.5 wide option rims instead of 6 inch ??? on the A cars and the rotor is BEHIND the spindle and in 71/72 ish big ball joints//different calipers-spindles to accommodate the 14x6 rally rims ??