Ok I guess I'll try again as I thought I had this right but not sure.
On the front fixed sight the ONLY difference in heights are the sight post. The a frame part of the sight are all the same correct. I put a flip and fixed sight side by side and see no height difference. The reason I ask is I'm gonna use a fixed handle barrel assembly with a flat top reciever and I want the sight to be correct before I waste time sights it.
As always thx
LLEASTWOOD

You're not asking the exactly correct question.

There is actually a slight difference in the sight base between F and standard sight base:



But the F base, which is the standard for flat top receivers will accommodate both a removable carry handle type sight and regular fixed or flip up sights. At least they do on mine.

Using a standard sight base with flattop receiver is where you could need a taller front sight post, as I understand it. And I guess the F with A1/A2 type receiver could be the opposite problem, a worse one, cause you can't get a "shorter" post.

- OS