just curious what was upgraded in your 4l60e? did you go all out, upgrading sun shell, better clutches and shift kit, 5 pinion planetary? you feel strongly about 4l60e's not being able to take the power and have me considering the swap too. i recently replaced my transmission and was thinking upgrade and rebuild the original. you have me second guessing this decision.
Billet servos (both of them), beast sunshell, upgraded band, upgraded frictions, and a TransGo HD2 kit. That's just what I bought. I'm sure my builder took some other liberties that I'm not completely aware of. Not positive about the five pinion planetary but I would assume. Total cost on the build and install was $2700 not including the parts I brought in, from a very reputable local builder.
That rebuild lasted about 10K miles. The first 3-4K were run with torque management zero'd out in the tune, which I'm sure is part of the reason it died so prematurely, but needless to say I expected a little more life than that.