Tim, my 468 that’s in my nova has 7/16 dimple rods with arp bolts (factory hi perf). My pins are pressed and it has 11-1 .250 dome TRW forged pistons that are close chambered but I have open chamber 116 cc aluminum heads on it= 10.25-1You need to be careful when you mill the heads to make compression. Your intake bolts will not lineup very good if you take too much off and you will have to slot the intake bolt holes a little bit. It also messes with your gasket surfaces. And you can also change the geometry by decking the block. The only way to know for sure is to mock up the new pistons in the block and check your deck height in each hole on the corner. Mine ranges from .006 to .012... my block had a lot of nickel in it and is extremely hard. Most big block Chevy’s only have a couple thousands wear And will usually clean up with just a light hone and de glaze. The machine shop should be able to run a deglazing hone in it and then make it and let you know if the cylinder has any taper or wear.
personally I think it would be pretty tough to get close to 600 hp with less than 10 to 1 compression. It could probably be done but you will have to do your homework. If you look at most GM performance crate engines most of them that make 600 hp are at least 10 to 1. Having zero deck height helps. If the Pistons are still in it you can clean the deck surface and you can check all the corners at TDC to figure out what your deck height is for your quench. another nice possibility is head gasket thickness. Standard is .042 and are available in different thicknesses. I run 91/93 octane in mine.
personally I think it would be pretty tough to get close to 600 hp with less than 10 to 1 compression. It could probably be done but you will have to do your homework. If you look at most GM performance crate engines most of them that make 600 hp are at least 10 to 1. Having zero deck height helps. If the Pistons are still in it you can clean the deck surface and you can check all the corners at TDC to figure out what your deck height is for your quench. another nice possibility is head gasket thickness. Standard is .042 and are available in different thicknesses. I run 91/93 octane in mine.
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