The studs are installed semi-permanently into the threads of the exhaust manifold holes. They go in just like the bolts, but with a threaded end versus the head of the bolts you are currently using. You then slide the flange over the studs and tighten down with a nut and lockwasher.
See the pic, it should be pretty clear how they work.
https://moyermarine.com/product/exha...exht_05-2_321/
Not sure why you mentioned t-bolts, I never talked about them and they are a very different animal and purpose.