Older MP electric distributor

I have kinda a dumb question.

Is there a way to adjust the factory vacuum advance canister?

i am running 18 degrees intial with 14 mehcianical. (I got help on here last year in figuring that out)

The car runs great with that set up, without the vaccum advance hooked up.

With it hooked up, I swear I can here those rattles(ping) a little bit when I get on it.

So I disconnected it and drove the rest of last year without it. I have now been reading another post about the benefits of running with the advanced attached.

Is it possible that my vaccum canister is bad? Or can it be adjusted? Or am i crazy and not making any sense??

Thanks!

Shane