Tail thickness Vs fin box setups

Ok guys heres the deal, I have been shaping my first board, and have taken the tail thickness down quite a lot. I had bought FCS plugs to install when I bought the kit for my board but I fear that my tail doesn’t have enough foam for me to drill into, I have made a few mistakes along the way but feel if I progress any further that this one might be irreversible. So my question to you is, what other fin boxes might be good to use in this situation, or are glass on fins the way forward for me? Please Help :) 

  No biggie...

  Just rout as normal, the top back of the box sticks thru into the deck, so add 3 layers of glass over it.

  I hate thin tails.  I have the power to sink most thick rails, so why use thin tails?

Like LeeD says, you can drill it out and if it goes through, install it, then sand it smooth and glass over. Don't know how thin you got yours, but most likely it won't happen. I've made some pretty thin boards that I put the old style plugs in and they got close, but didn't go through.

See if you can trade the plugs in for Fusion boxes. It’s a better system anyway, IMO.

I'll second what nj_surfer said. Easier install also.