Gears for ICS M4 with Upgrades?

[Death March]

Hey guys,I'v checked the FAQ's and did't qwite find what I was looking for so here goes! I have an ICS M4A1 with an MA-56 upper gear box it has a M120 spring and chroned at 396 fps with .25s.Now I had the motor back off on me about a year and half ago,kinda nicked the tops of the gears but I got it time before there was any real damage.But I did re-use them when I did the up-grade and the gun was not sounding right so pulled it apart and sure enough one tooth from the spur gear was missing.Now when I did the upgrade I did re-shim the gear box and I think thats what saved it.Anyway what would be the better Gears too go with Systema regular hardend or the Torque up set.I just want it to be built right and I'm not worried about alittle drop in R.O.F. I have a Classic Army high-Torque motor in it as well and use a 9.6v 1700mAh battery.I'v been using this upper set for the past two and half months before the gears gave out.I knew I should have replaced them when I put the MA-56 set-up in.Has anyone tryed Systema gears in an ICS is I guess more of what I'm driving at? Any advice on this would be great,Thanks ! :grin: