Definitely need the harden head bolt washers
I haven't and probably won't use beaded steel head gaskets on aluminum heads
How about port matching the intake ports to the intake gaskets and check that gasket to the intake manifold to make sure the manifold ports are NOT bigger than the head ports
Same thing on the exhaust side, make sure the header flanges holes are bigger than the head exhaust ports are
On the size of the header pipes you CAN"T go to big
Especially on a street car