Yea I have the original distributor
And yes you confirm advance is working with timing light
But can confirm vacuum is ok at the hoses by unplugging and using a finger at the hose opening.
As stated above, I confirmed mine were installed backwards by the prior owner
https://forums.pelicanparts.com/porsche-911-technical-forum/1144485-1983-ignition-timing-vacuum-hose-question-2.html#post12064425
I’m all set now. Just need to check my timing this weekend and put this behind me.
Unfortunately I’ve experienced almost 20 years with my 911 not accelerating as optimally as it should. I’ve never driven another air cooled 911 so I had no point of reference and there was no obvious issue. I only discovered the hoses were backwards when I started diagnosing a power loss under light load at 2k RPM. Power loss is gone now. I believe a combination of the distributor mechanical advance needing lubrication and not having the vacuum advance properly connected to assist with low load advance was causing my power loss at 2k RPM. If that power loss had not happened, I would still not realize the hoses were backwards and I would be ignorantly believing my 911 performance was normal.
A good learning experience and if you have a late SC with 2 vacuum hoses at the distributor, it is best to check they are connected properly