I cant find anything anywhere supporting your claims of hardened parts, valve body changes, or clutches. GM hasnt changed the 4T65 as far as im aware when it comes to the w-body. Also looking on trannymans site there is no price difference when it comes to these transmissions. Now the Volvo 4t65 has a different valve body but not ours. The flex plate is only different due to the differences in torque converter sizes. But thats more of a NA block versus SC block thing rather than a year specific issue.
