I'm going to consider that one myself for my '68 C-30, altho my problem won't be the E-Brake, but I have a "Self-Contained" PTO unit under there that I bet won't work with it.
I'm sure there will be others jumping in soon to answer your individual questions, but in the meantime jump over to my "2-Ton 5-Speed in a 3/4 or 1-Ton" thread and you will see some info on it. Grigg also gave us a good link to check out.
Right now my best bet with my C-30 is to put in a higher gear in the rear-end as with the SM 465 I have in there, I can afford to lose a little on the start off and first should still be a good enough off-road gear.
Bill