dwm, what trans will you be using in that '63? My son has a '66 and he's asking himself that question also.
His has a TH-350 now. Option's he's considering are 2004R, Muncie and T-5.
I have an sbc powered street rod with a 2004R and a 3.80 rear axle ratio. The OD 4th gear is sweet for freeway driving.