I made a fitting for neoprene hose to work with vacuum gauge. Basically cut a hose barb and fitted into the vacuum fitting; a little JB weld epoxy to seal it good, and just had to slide the hose over the barb when gauge cluster installed. Easier than using metal lines and getting it all in there and not kinked.
Then wired-up the gauge cluster to attach with connectors under dash. Just need to finish the instrument lighting connections and dash will be done.