Replacement AR front sight question

[RAMCHARGER]

I purchased a standard A2 front sight to replace the gas block I have on my AR carbine now.
However there is no "F" mark on it so I guess it will be too tall/short for my rear BUIS or is it close enough?

[damon1272]

The F marked ones are for carbines. You can use a standard sight but may run out of adjustment to make it work. You couls also try different ammo to see where it hits.