Trick Flow small block heads

OK... normally aspirated, under .570 lift flat tappet hydraulic with 9.5-10.0 compression.
Should I use studs or bolts to fasten the heads?

Bolts work fine,
I re use the old factory head bolts or pull some from the wrecking yard on factory iron stuff. You aren't in the range of pushing head gaskets and needing head studs imo.
I've run a lot more and never have.
12.1 225psi and up..you bet, but not this.
Ultimately though ..run what they recommend.