Header back exhaust kits?

I am installing a Jegs 2.5 as we speak to my dougs headers.

They seem to be way too long of reach to mufflers. I would guess 6-10" too much
to place the muffler at the hanger position. I am about to hang mufflers and measure..

Oh yeah....68 barracuda fastback.

Also..4 of the pipes were mislabelled