replacing exhaust studs brass nuts with stainless bolts

[42south]

Hi Guys
I am planning a top end refresh in the medium term and am interested to know of others experience replacing the exhaust manifold studs,brass nuts combination, with Stainless bolts, and either a spring washer or a Nord lock washer.
I can get 316 stainless bolts in 5/16th UNC down here in the Antipodes, and Nord lock washers are also available in Stainless or galvanised.
Having had the brass nuts loosen leading to a gasket failure, I'm looking for a better alternative
I know some members have done this and would like to hear of their experiences good or bad.