You may want to ask that question here:
http://www.rcgroups.com/forums/forumdisplay.php?f=129
Some of those guys are very experienced with adapting Polyquest-type taps to TP taps. Just make sure that they are aware that you want to charge both 3s packs at the same time as a 6s pack.
SH Z-Car, Custom Crawler, 8s Savage,
12s XTM XLB 1/7 buggy,
4wd 4-link rear/IFS Pro4 truck,
Custom Hyper 10 Short Course,
Belt-Drive Mammoth ST 1/8 truggy, 4s 17.5 MM Pro HPI Blitz