I was wondering if I could get any pointers on how to change the gears in my 98 Cobra to the FRPP 4.10s? I once heard that when switching them I would not have to swap out and mess with the shim, but to use the existing one. My father will be doing the install, as he has done these before and built several 1930s street rods. He is just unfamiliar with the Cobra. He just would like some reassurance that this process will not blow up in our face, i.e. his 66 Chevy II nova required several changes that took a lot of time and money. Any help would be appreciated. Thanks. Ryan