Proportion Valve Problems

What do you mean by the octagon shaped adapter? That would be some sort of 8 sided piece. The parts I have pictured are off of 70-71 a-bodies with disc brakes . Inline tube shows pics and PN#'s find yours and post the number you need. I just bought one for a 70 challenger Same as A-body but has a mounting stud vs. hole
It needs to have this fitting. I don't have the one that came on my car.. I purchased 2 re-pops and they both leak.. I'm looking to buy an original.

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