I have a 96 G10 Brake Booster/master and trying to figure out what line sizes/flares connect to the two master cylinder ports. One port is larger than the other, I think the larger connection is for the front brake line? Also, the brake lines are missing. Are 3/16 double flare lines correct? The larger port connection doesn't look to fit a 3/16 line.

 

Researching for hours online and can't find any specific information. Do I need to buy a shop manual?

 

What about going to a wrecker and see if there is on there to measure the lines.
Also call the dealer parts desk and ask for the sizes. They should have explode diagrams on the computer.