K-member mounts

And where would I get that? I have a PDF of a "factory" manual but it doesn't have any frame/body dimensions.
They are in the service manuals, you may have to try a different year manual. Wheelbase varies, not the K form 67/ later MyMopar is the download site

EDIT Here ya go the 69 Dart/ Cornet manual, page 23-111

Click the black icon in the box and "save as"

EEEEEEEEEEEEEEAAAAAaaaaaaaaaaaaaaccccccckkkkkkkk!!! I see they don't show the K member mounts