F marked, or not F marked... do I really need it

[shibbershabber]

So I am putting a flat top upper on my rifle that used to be in a traditional A2 configuration, but I want to scope it.

There currently is a standard A2 FSB on there.

I know the F marked ones are a bit taller to accommodate sights mounted on the flats

Is this assuming an A2 handle/sight or any sight???

In looking at the options, I see that the bolt on carry handle sights clearly need the higher FSB, however, the Magpul buis arent that tall... can I use them in conjunction with the standard height FSB????

ANyone know?

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[Garg]

That's a good question.
Here is what I found on AR15.com

http://www.ar15.com/archive/topic.html?b=3&f=4&t=309307