i don't see how the 4L60 has lasted you longer than the 700r4. they are identical transmissions. The only difference is the 700r4 is vacuum and the 4L60 is electronic. I hear lots of guys saying that the 700r4 and 4L60 are junk. It all depends on who's building them. If you don't know what your donig, and yes, there are lots of tranny shops out there that don't know how to build one the right way, it won't last. I have a 4L65e(built up 4L60) in my truck now and I drive the crap out it. also have a 700r4 in my buggy that gets driven just as hard. never had problems with either. But I also had a buddy that knows how to build them go through mine. just my 
The l60 is in a MUCH milder rig...that's how
. I'm just sharing my PERSONAL EXPERIENCES, we can agree to disagree, just saying it is the absolute LAST trans. I'd ever consider for wheeling personally, and I'm certainly not alone.
Back to the OP's questions, I'd trust the cases before the trans., that was my only point.BTW, how is it possible that you can rationally say your trans. gets used "just as hard" as mine??? Do you know my rigs? Do you know my trails? Have you seen me wheel? I'm not saying I wheel harder or wheel harder trails because that is simply ignorant...I have no clue.
