318 engine combination

Let's fix some errors: The deck height above seems a bit low, even for a Magnum block. An LA block will have around 9.599-9.600" deck height. So with a 1.810 compression height, these pistons will end up about .012 below deck in a LA block. No problem to get about .040" quench with a .028" head gasket (Mr Gasket 1121G).

So OP, what year is your 318 block? We just need to know if it is before or after '92 IIRC to decide if it is an LA or Magnum block.

With 64 cc chambers (my recollection for the 302's but check me on that) and a .028" head gasket, that is around 9.5:1 in an LA block.

OP, what do you intend to do with this engine? Drag race? Road race? Circle track? Cruise? That has a lot to do with what you decide next. You asked about how much HP.... that can be all over the place, depending on the cam and the in and out breathing bits. But the cam should not be chosen for peak HP alone; it will decide the 'character' of the engine and should be tailored more for the intended use. So let us know a bit more of how this will be used.