I looked over Rock Auto too and noticed the ring gear tooth count of 191 of the V6 ring gear and the 139 of the 6.2 gear as well as the difference in diameters, seems to be close to about 1 3/4 diameter difference. What ever Tilton did on my Flywheel definitely worked and matched the diameter exactly to the 305E Flywheel but it is making me question whether it really is a 6.2 ring gear or something else like a ring gear off a medium duty truck with a 366 or 427. Initially I did have some conflict with them and it took well over a year for them to get it done.