Lowering the pickup, or, other setup adjustments, are the way to fix the string hitting pole pieces.
Not tape.
You can download a good basic G&L setup guide from the G&L guitar FAQ section:
http://www.glguitars.com/faq/index2.asp
look for this part:
Q. I lost the the User's Manual which came with my G&L made in the 1980s to early 1990s. Where can I get a copy?
A. Original printed versions are no longer availble, but you can download a PDF version.
Please note that models since the late 1980s, particularly 4-bolt guitars and 6-bolt basses, do not come with owner's manuals. The manual for earlier models covers how to adjust the micro-tilt neck feature no longer used on 4-bolt and 6-bolt models. Other aspects of the manual, such as pickup height adjustment, generally apply to newer models.
the "spring ping" is easily cured, as noted above.