My problem was not the first gear, both the 3.09 low from 64/65 and the 3.09 from the overdrive, and the 2.66 from the standard A833 in my stock; are all the same MS gear .
My problem was the huge overdrive gear on the cluster. I would have had to cut my standard 2.66 cast-iron case at least .25 to .38 inch in that area (IIRC), just to get to zero interference. That's a chitload of work, and if I cut thru, ........ so I just put it all back into the aluminum box and got the proper BH. The local JY had a pile of them
