I always found/thought those little metal plates that came with the intake gaskets were way too thick and was afraid it might crack the manifold in the center when torqued down.

Ever since I use an old intake valley pan and cut out a few plates myself with tin snips.

Non of my cars have a (working) heatriser in the exhaust anymore, but then again they're not daily driven either.
The only old car that gets driven daily is my '73 Dodge Dart and since it runs on propane I preferrably don't want any heat in the intake as it simply because it robs power, makes the engine heatsoak more and feel lazy.