Hey Guys,
correct me if i am wrong, but i am pretty sure that the early t3 brakes (62-63 ) are NOT the brakes you are looking for, for the big brake conversion. Those brakes aren't much bigger (if any) from an early set of bug brakes. For the big brake conversion, as Geoff mentioned, you need the 64-65 rear backing plates for 5 bolt, or the 66 and later for the 4 bolt conversion. The parts that you need, that you can't buy new, are the backing plates, the e-brake levers (i think) and i had troubles with the new brake shoe retaining hardware, such that i needed to find used pieces. To source these parts, start by asking Airspeed, otherwise talk with Anthony at ISP West, he hooked me up and new exactly what i needed.
If you are looking to do the T3 big brake conversion on a earlier bug that has the short axles, you must also machine off part of the brake drum (the outer most \"nipple\" where the axle bolt touches the drum). You end up machining off between 1/2\" to 5/8\" (argued).