Slightly strange head flow question.

Maybe this will help

XS282S Cam - .520/.540 lift @ .50, 244/252 @ .50 duration, recommended 2500-6500 rpm

If I have access to two two pairs of identical Edelbrocks (springs valves etc)

- one set flows 260cfm at .550, the other 290cfm at .650,

For arguments sake, lets say both display "healthy" low-mid lift figures also.

Which should I use and why?

Assume the cam, M1 SP, 800cfm carb and everyting else will not be changed.