I have a 88 5.0 TPI and replace my rear a while back from drum to disc and do I really need to replace the valve from a drum to disc type and if I do does anybody know the part# to this type valve for disc. thanks

 

from what i understand you need the one that is machined from a piece of aluminum and not the cast iron one. any gm parts dept. should be able to find the part you need. numbers often change so a number good last year may of been replaced even though it's the same part.