If you can, wait a few months. GM is producing a 4l70E. It is identical to a 4l60/65e, but it has more hardended parts. The 4l65e's planets are better, but they are still breakable, ask me how I know. I did it in my daily driver. Rarely do old style 4 pin planets break.

The torque rating on the 4l70E is much higher than anything currently offered, thus the 70 designation. Some say the rights to this product were purchased by GM for use in the SS Trailblazer and future 4 speed auto trannies until the 6 speed auto is released in all autos. http://www.torquedriveinc.com/