Proper Dimension LVL for a 6' Load-Bearing Span?

That's it. I've got a 6' section of bearing wall open and held up with 2x4 tee-jacks and 2x top and 1x bottom plates. All is well, but I want to get the right size LVL to use for supporting the span. I can get 11 7/8", but if I can get away with less coming down off the ceiling I'd prefer to do that. I can always build down from it once the thing is up, and get the height I want for finish. Anyone an expert on engineered wood? Thanks for your time...