Vacuum hose..

Long story short, I've been flying our -6 without a DG and AI for a couple years and figure it's time to reinstall them.

I've moved a handful of times and cannot find the original vacuum lines that were in the aircraft so I'm looking at new.

Anyone running automotive silicone vacuum lines? $20 @ 10' is much nicer than $8.95/foot at Spruce.

Is this a terrible idea?

It is an excellent idea. Coincidentally, I just took all mine out tonight for a panel upgrade, and it was like new after 15 years. Be sure it is real silicone and not some thermoplastic that will get hard and be very difficult to remove.

I don't know what automotive application would have large enough lines for the flow you need.

I had two different ones, some braided stuff for the higher vacuum to the pump, and non-reinforced thick wall stuff for the regulated (lower vacuum) side.