How to test fuel pump? How to attach pressure gauge?

Stock 1973 Dart 318 V8. The 1973 shop manual shows how to use a pressure gauge to test outlet pressure on the fuel pump. The book says to install a tee just before the carburetor to connect the pressure gauge. I don't think the tee fitting exists. Numerous auto parts stores do not have the fitting. IS there another way to test a fuel pump?

Fuel pumps are not that expensive. It seems way easier to just change the pump. That is wasteful to me.
So it's wasteful to actually test a pump rather than buying another and throwing away a pump that may be perfectly good?

The "fitting" is whatever it takes, and may and likely does consist of more than one fitting. On older systems, like Mopar, fittings are pretty much inverted flare--same fittings as brake lines. Due to modern auto stores "not being" as "partsy" as they once were, IT MIGHT BE more difficult to round up parts. But it can be done

You can buy various lengths and sizes of brake lines with inverted flare. You generally need 5/16"
You need a tee with adapters so that you can disconnect the existing line, put the tee inliine, and output a branch of the tee to the pressure gauge.

That pretty much is going to be determined by "what is in your junk box" and what the local stores have in stock. There are various ways of getting there

My question to you is "do you know and understand" the basics of various fittings, such as inverted flare, SAE flare, pipe thread, and so on?