OK, so, I am NOT going to do any other shift kit other than a jerry mod on my 4R70W, however, I was wondering, could somebody explain to me why the j-mod is the only suitable recommended "shift kit" for this trans? I understand the part about "go with what the guy who designed it says" and I agree. But what is it about the other shift kits, B&M, Lentech, etc. that are "BAD" for this trans? What exactly are they hurting, and what about the J-mod causes it to NOT have the issues the other shift kits cause?