Shaggy. Two thoughts for decreasing effective combustion chamber volume without a major engine tear down...
1) In the rebuild of Carol Miller's engine described in the link below, Ted Eaton reported that the 113 cylinder head deck surfaces had been milled ~.080 inch. IF this machining was pursued, you would have to make a compensating cut on the intake manifold mating surface of the cylinder heads for cylinder head to intake manifold alignment purposes.
See the link below for Ted's report on this engine build and the dyno results
http://www.eatonbalancing.com/blog/2015/05/01/unported-iron-heads-can-still-make-over-a-hp-to-the-cubic-inch/2) Today, composite head gaskets are commonly used to assure sealing the cylinder heads to the engine block. From '54 - '64 FoMoCo used steel shim head gaskets and so did everyone rebuilding or modifying their engines for years thereafter. Consider using the steel shim head gaskets to maintain the effective combustion chamber volume your engine came from the factory with. Composite head gaskets can increase your effective combustion chamber volume by several cc over original stock dimensions which significantly reduces your static compression ratio. I'm fuzzy on this, but I think that Dennis Carpenter is offering aftermarket steel shim cylinder head gaskets.
See the link below for Ted Eaton's report on the range of cc volumes of different manufacturer's compressed cylinder head gaskets.
http://www.eatonbalancing.com/blog/2012/06/30/head-gasket-volume-calculation/IMO, IF you were NOT avoiding a major tear-down of your engine, short of domed pistons, THE best way to raise the effective compression ratio of your engine would be to have the engine block squared and decked to accomplish zero decking the piston tops. It's regularly reported that stock production y-block assemblies have pistons below the block deck surface (in-the-hole) by .020 to .025 inch. Coupling this stock clearance with composite head gaskets compressed thicknesses significantly increases the cylinder head quench dimension and thereby increases the effective combustion chamber volume. These factors combined together torpedo your actual static engine compression ratios. IF you add a 'performance' intended camshaft with intake valve timing that closes the intake valve later after bottom dead center, your engine's low rpm performance, throttle response, and vehicle drive-ability suffer significantly because your engine's dynamic compression ratio drops. IMO, performance intended camshafts do not perform as intended (or desired) with low static compression ratio engines. IMO, street engines need 9.0:1 or higher static compression ratio for a longer duration camshaft to work effectively and not torpedo vehicle street drive-ability.
Hope this helps.
NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York