Motiv provides a symmetrical drlling guide on the Motiv website for their symmetrical core balls. Go to motivbowling dot com then resources, then trade resources for the link to Motiv's symmetrical drilling guide.
I use MoRich's drlling guides for all of my equipment (symmetric and asymmetric). These are found at morichbowling dot com using their product information, drillings link and dual angle layout technique, also from their homepage. For symmetrical balls, Mo provides a link on their homepage in the Perpetual Motion area.
MoRich mania: 25x4x25, P4, P1500
MoRich Craze: 40x4.25x40, P3.5, P2000
MoRich RipR: 45x4.5x40, P3, P2500
MoRich Perpetual Motion: 60x3.5x30, no hole, P3000
MoRich Frenzy: 45x4.5x50, P3, P3000
MoRich Mojave: 60x4.75x50, no hole, P4000
MoRich Spare, label negative, no hole, P4000
Edited by jbungard on 7/10/2011 at 4:35 PM