<VV> 1966 4-Speed to a 1965 Differential

[Steve & Doris Schwartz]

I will soon (or likely later) install a '66 4-speed into my '65 Monza 140.  I read in "How to Keep Your Corvair Alive" there is a need to grind relief in the differential flange face.  Does anyone have images they could forward to me?  I have not had this apart so it's all new to me.  Also, are there any modifications to the transmission that are recommended when I have it rebuilt (i.e. change gears for close ratio, anything, etc.)?  Any other advise is welcomed.  

Steve
140 VAIR