Working with Tap & Dies

[ARRX7]

Hello! I'm new to the forum and new to fabricating stuff on my own. I figured it's time for me to step up (and save money).

I just purchase a, gulp, harbor freight tap and die set (standard) to place a threaded hole in a block off plate on my intake manifold.

The tap is 24 threads per while the brass nipple I was planning on using (boost nipple) is 27 per, so I'm thinking, this ain't gonna work.

My question is can I expect to find brass fittings with 24 threads per or have I purchased a tap and die kit that just doesn't work with most bolts, nipples, or anything else I may come across in a typical hardware store? TIA

~M