If your car has an Automatic Trns you will need vacuum for that. The vacuum shutoff can be replaced with a self fabricated manual one.
The door locks only need a small vacuum pump.

I am interested in replacing my Vacuum Pump with an electric one also as I have 2 cars with Vacuum Pumps.
I am bidding on one of the 12 volt Thomas Vacuum pumps on Ebay; but have no idea if it will be enough for the job. Also the pump pulls 8 amps and I may have to get a higher AMP alternator.
These cars are supposed to be equiped with Vacuum Pumps for the brake booster (I got this info from EV-Electric Vehicle sites) as I believe these models had turbochargers.
Buick-1982 Skhyhawk J and 82-85 Skuylark X
Cadillac- 82 Cimmaron
Chevy- 84-86 Celebrity A, 82 Caprice B, 82 Cavalier J, 83-85 Citation X
Oldsmobile- 86 Cierra A, 82 Firenza J, 82-84 Omega X,
Pontiac- 85-86 6000, 82 J2000, 82-84 Phoenix X
After a 3 hour search of the local junk yard I found not ever 1 of the above cars.
A new Vacuum Pump for the above cars is supposed to be arround $300 and the GM part number is 22034995

Google and look at the EV sites and some will have a picture of the GM Vacuum Pump. It is found under the fender well with a plactic cover over it or inside of the engine compartment near the Booster.

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84 300D, 82 Volvo 244Gl Diesel