Hi. Just picked up a 15# Zr40. Is the core symmertical or asymmertical? I can't find the info on the Dyno-Thane web site. Also there is a 1/8" black perfectly round spot on line with the pin, cg, mb but it is about 9" away from pin. Is this spot there for a reason? Never had a Dyno-Thane before and am looking forward to drilling this up and trying it out.
Thanks
Dick