SRT6 trans will hold, but even it is not as strong as the V8 trans, and lacks some of the improved shift elements (blue top solenoids). The bigger difference is the torque converter. With the torque of the V8, it will have a slightly higher stall speed. Not a big deal. As for swapping the yoke, you will need to get the nut off the tail shaft of the trans, and probably need a gear puller to get it off, the swap, put the nut back on and peen it in place.