A833 was introduced for the '64s; '63s used the B-W T10 for non-Maxie cars. No Maxie 4-speeds 'til '64. You could use the T10 but the A833 would be less of a conversion. Tail housing should be B-body, which locates the shifter for an early B also. Some fab work's required on the trans crossmember, but I've used a '68-'69 trans mount in the early crossmember and it works fine.
I also updated MC & brake lines, driveshaft/U-joints & rear axle on my '63 & '64 cars. '66 speedo cable adapts later trans to early speedo. '63 - '65 clutch linkage parts appear the same to me, but both of mine were already 3/tree cars. I used a Centerforce 10.5" clutch. RB motors are tight at the early-B rt apron. Fan shroud mandatory with a BB. Early-B motor/trans sits well forward of '66-later, so fan clearance is tight even w/o a fan clutch.
