Ryan,
anything under 550 i would not use a jag diff, i would use a 7.5 plated item or a Quiaffe or Gripper.
personally i would use this setup at std power as even that fooks sun/planet gears in teh std units, up from that a good 400 power plant will fook a high mileage cwp , and try and find a low milage cwp these days , there arnt any.
i also recomment tom seal's gripper diffs , used thena few times , excellant kit