Sorry, sometimes it's hard to tell someone's skill level through the internet. No you don't need a vacuum schematic to check the system they are very basic. All you have to remember is that anything between the base plate of the carb. and the manifold needs to be checked. This includes the manifold itself on the small chance of a hairline crack, all fittings that screw into it (except on the front most coolant runner), all around it's gasket surface, all hoses coming out of it and the carb. all along there length and where they terminate. you also need to check things like the modulator valve if auto, the vacuum advance dashpot on the distributor and the power brake booster if you have one. The best way to check these is with a hand held vacuum pump like a mity vac as they are inexpensive. As a mechanic doing it for a living years ago I always found oxygen if you have a set of torches the easiest and cleanest to sniff out the leaks in the hoses and such while idling as it will cause the rpms to raise up when there is a leak. If none a home plumbers torch with propane works just as good and some people use carb. cleaner but be careful if you have a pretty engine as it can discolor some paints, also be careful when spraying near a hot manifold. For these reasons I like the above two methods better. Also as I said don't forget to check all around the baseplate of the carb. but be careful if you have an open element air cleaner as it can suck it through the filter and fool you. This whole process won't take you more then 20 minutes to a half hour at most.