Glenn Ashmore wrote:

If you can't clamp a 10' 6x6 you ain't got enough clamps! No
respecting DIYer can have less than a dozen bar clamps.

Yea, I got lots of bar clamps, but I can't clamp around the posts
because the fence is already up in between the posts. Maybe fence
isin't quite the right word. It's not a wood fence - it's
poured-in-place concrete. So it's not coming out.

I don't think they make C-clamps with arms that are 8 feet long.