For a race engine you should use the rocker arm ratio that most race lobes are designed for. That way you are in the "sweet spot" when it comes time to spec a race cam. Talk to Dwayne or flip thru some cam lobe catalogs and you'll see that 1.70 or 1.80 are probably the best choice for a big race engine. At least on the intake side. You should be able to get by with less ratio and less spring on the exhaust side.