gggdds

I have a 76 911s with the oil cooler in the right front wheel well

Reiver

fill it with 9.5 quarts, run it until fully warm (all thermostats open about 200 degree's or so) then check your dipstick. You want to be center or half way between the two lines....never to the 'full' mark as you'll overfill and make a smoky mess.
It can only be really checked, topped off, when running at normal temp....never cold.
BTW, it will run rough when you open the oil cap...that is normal...if it does not run rough you have an air leak somewhere.