Barcus Berry 1457XL - Manual (Page 9)

diameter hole through the end block where the Fas-Jac
is to be installed.
4) Insert the 1/4” diameter rod into the guitar through the
hole in the end block until visible through the sound hole.
5) Push the rod into the Fas-Jac and pull the Fas-Jac
through the end block until it is stopped by the nut
threaded onto the body of the Fas-Jac.
6) Measure the length of the exposed Fas-Jac threads
visible on the outside of the guitar. The length of the
exposed threads must measure at least 1/8” (but not
more than 5/32”). If the exposed length is not correct,