Holley recommends cut the vacuum number in half to get the power valve number. If they don't make that exact power valve number round down to the next one.

best of 11.24 at 119 mph 1.60 60’. 68 340 S Barracuda Fastback F.A.S.T [IMG]http://i67.tinypic.com/2mnnnnt.jpg[/IMG]