Keep breaking 3rd gear

the 3rd gear in a mopar trans is the weak link. if you're lifting off throttle and then punching power back on, its taking hell of a beating!!! also clutch probably doesn't slip to absorb some of the power?? we use a soft loc it will slip and absorb the power, without breaking parts. might try a jerico trans, the gears are straight cut and very big. I think clutch needs to be looked at also .just food for thought.