Change from rear drums to disc

[Doug Larsson]

I purchased rear disc brakes for my 73 a couple years ago from Classic Industsries. I'm getting the itch to tackle the build. The only thing off the top of my head I'm concerned about is pulling the axles to convert it I have the 8 1/4 rear end in mine. Is there any thing I need to know when doing this. Also I rebuilt my proportional valve awhile back. The company who sent me my rear disc brakes told me I can still use my stock proportional valve set up. Has any one did this project and used the stock one ?

 

[aeon280]

I did rear disk on my 67 and still run the factory proportioning block without issue.

 

[Doug Larsson]

I did rear disk on my 67 and still run the factory proportioning block without issue.

One guy on another site said it might rub the rear disc because those are made for drum brakes they could rub constantly. I've never heard of that though.

 

[aeon280]

One guy on another site said it might rub the rear disc because those are made for drum brakes they could rub constantly. I've never heard of that though.

Hmm, that doesn't make any sense. The prop valve essentially limits the pressure to the rear to prevent the rears from locking up under light braking. With a front disk/rear drum setup you need to put in an additional valve to further restrict the drum pressure but with disk/ disk its the same as drum/ drum. Less fluid pressure sent to rear than to front by the factory unit. if you have concerns just put in an added prop valve https://www.summitracing.com/parts/...XondC1ZYGfG8S2w52opfBap5RFe6zxkUaAi4yEALw_wcB and you can adjust the rear pressure accordingly. I have one on mine when I was running disk/drum and just never took it off when I swith to disk/disk but its run wide open so essentially does nothing.

 

[Doug Larsson]

Hmm, that doesn't make any sense. The prop valve essentially limits the pressure to the rear to prevent the rears from locking up under light braking. With a front disk/rear drum setup you need to put in an additional valve to further restrict the drum pressure but with disk/ disk its the same as drum/ drum. Less fluid pressure sent to rear than to front by the factory unit. if you have concerns just put in an added prop valve https://www.summitracing.com/parts/...XondC1ZYGfG8S2w52opfBap5RFe6zxkUaAi4yEALw_wcB and you can adjust the rear pressure accordingly. I have one on mine when I was running disk/drum and just never took it off when I swith to disk/disk but its run wide open so essentially does nothing.

I agree with what your saying the company I bought the kit from I called them and he said you should be fine. But there's always a bunch of guys on Facebook that tell you it won't work. I know when I come on here I get the no bullshit answers I'm looking for.
Thank you